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| Meta Description | Objectives and metrics. Used for optimization. Objectives and metrics MAE. | ||||||||||||||||||
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| Boilerpipe Text | Objectives and metrics
Used for optimization
Objectives and metrics
MAE
∑
i
=
1
N
w
i
∣
a
i
−
t
i
∣
∑
i
=
1
N
w
i
\displaystyle\frac{\sum\limits_{i=1}^{N} w_{i} | a_{i} - t_{i}| }{\sum\limits_{i=1}^{N} w_{i}}
Usage information
See
more
.
User-defined parameters
use_weights
Use object/group weights to calculate metrics if the specified value is
true
and set all weights to
1
regardless of the input data if the specified value is
false
.
Default:
true
MAPE
∑
i
=
1
N
w
i
∣
a
i
−
t
i
∣
max
(
1
,
∣
t
i
∣
)
∑
i
=
1
N
w
i
\displaystyle\frac{\sum\limits_{i=1}^{N} w_{i} \displaystyle\frac{|a_{i}- t_{i}|}{\max(1, |t_{i}|)}}{\sum\limits_{i=1}^{N}w_{i}}
Usage information
See
more
.
User-defined parameters
use_weights
Use object/group weights to calculate metrics if the specified value is
true
and set all weights to
1
regardless of the input data if the specified value is
false
.
Default:
true
Poisson
∑
i
=
1
N
w
i
(
e
a
i
−
a
i
t
i
)
∑
i
=
1
N
w
i
\displaystyle\frac{\sum\limits_{i=1}^{N} w_{i} \left(e^{a_{i}} - a_{i}t_{i}\right)}{\sum\limits_{i=1}^{N}w_{i}}
Usage information
See
more
.
User-defined parameters
use_weights
Use object/group weights to calculate metrics if the specified value is
true
and set all weights to
1
regardless of the input data if the specified value is
false
.
Default:
true
Quantile
∑
i
=
1
N
(
α
−
I
(
t
i
≤
a
i
)
)
(
t
i
−
a
i
)
w
i
∑
i
=
1
N
w
i
\displaystyle\frac{\sum\limits_{i=1}^{N} (\alpha - I(t_{i} \leq a_{i}))(t_{i} - a_{i}) w_{i} }{\sum\limits_{i=1}^{N} w_{i}}
Usage information
See
more
.
User-defined parameters
use_weights
Use object/group weights to calculate metrics if the specified value is
true
and set all weights to
1
regardless of the input data if the specified value is
false
.
Default:
true
alpha
The coefficient used in quantile-based losses.
Default:
0.5
MultiQuantile
∑
i
=
1
N
w
i
∑
q
=
1
Q
(
α
q
−
I
(
t
i
≤
a
i
,
q
)
)
(
t
i
−
a
i
,
q
)
∑
i
=
1
N
w
i
\displaystyle\frac{\sum\limits_{i=1}^{N} w_{i} \sum\limits_{q=1}^{Q} (\alpha_{q} - I(t_{i} \leq a_{i,q}))(t_{i} - a_{i,q}) }{\sum\limits_{i=1}^{N} w_{i}}
Usage information
See
more
.
User-defined parameters
use_weights
Use object/group weights to calculate metrics if the specified value is
true
and set all weights to
1
regardless of the input data if the specified value is
false
.
Default:
true
alpha
The vector of coefficients used in multi-quantile loss.
Default:
0.5
RMSE
∑
i
=
1
N
(
a
i
−
t
i
)
2
w
i
∑
i
=
1
N
w
i
\displaystyle\sqrt{\displaystyle\frac{\sum\limits_{i=1}^N (a_{i}-t_{i})^2 w_{i}}{\sum\limits_{i=1}^{N}w_{i}}}
Usage information
See
more
.
User-defined parameters
use_weights
Use object/group weights to calculate metrics if the specified value is
true
and set all weights to
1
regardless of the input data if the specified value is
false
.
Default:
true
RMSEWithUncertainty
−
∑
i
=
1
N
w
i
log
N
(
t
i
∣
a
i
,
0
,
e
2
a
i
,
1
)
∑
i
=
1
N
w
i
=
1
2
log
(
2
π
)
+
∑
i
=
1
N
w
i
(
a
i
,
1
+
1
2
e
−
2
a
i
,
1
(
t
i
−
a
i
,
0
)
2
)
∑
i
=
1
N
w
i
\displaystyle-\frac{\sum_{i=1}^N w_i \log N(t_{i} \vert a_{i,0}, e^{2a_{i,1}})}{\sum_{i=1}^{N}w_{i}} = \frac{1}{2}\log(2\pi) +\frac{\sum_{i=1}^N w_i\left(a_{i,1} + \frac{1}{2} e^{-2a_{i,1}}(t_i - a_{i, 0})^2 \right)}{\sum_{i=1}^{N}w_{i}}
,
where
t
t
is target, a 2-dimensional approx
a
0
a_0
is target predict,
a
1
a_1
is
log
σ
\log \sigma
predict, and
N
(
y
∣
μ
,
σ
2
)
=
1
2
π
σ
2
exp
(
−
(
y
−
μ
)
2
2
σ
2
)
N(y\vert \mu,\sigma^2) = \frac{1}{\sqrt{2 \pi\sigma^2}} \exp(-\frac{(y-\mu)^2}{2\sigma^2})
is the probability density function of the normal distribution.
See the
Uncertainty section
for more details.
Usage information
See
more
.
User-defined parameters
use_weights
Use object/group weights to calculate metrics if the specified value is
true
and set all weights to
1
regardless of the input data if the specified value is
false
.
Default:
true
LogLinQuantile
Depends on the condition for the ratio of the label value and the resulting value:
{
∑
i
=
1
N
α
∣
t
i
−
e
a
i
∣
w
i
∑
i
=
1
N
w
i
t
i
>
e
a
i
∑
i
=
1
N
(
1
−
α
)
∣
t
i
−
e
a
i
∣
w
i
∑
i
=
1
N
w
i
t
i
≤
e
a
i
\begin{cases} \displaystyle\frac{\sum\limits_{i=1}^{N} \alpha |t_{i} - e^{a_{i}} | w_{i}}{\sum\limits_{i=1}^{N} w_{i}} & t_{i} > e^{a_{i}} \\ \displaystyle\frac{\sum\limits_{i=1}^{N} (1 - \alpha) |t_{i} - e^{a_{i}} | w_{i}}{\sum\limits_{i=1}^{N} w_{i}} & t_{i} \leq e^{a_{i}} \end{cases}
Usage information
See
more
.
User-defined parameters
use_weights
Use object/group weights to calculate metrics if the specified value is
true
and set all weights to
1
regardless of the input data if the specified value is
false
.
Default:
true
alpha
The coefficient used in quantile-based losses.
Default:
0.5
Lq
∑
i
=
1
N
∣
a
i
−
t
i
∣
q
w
i
∑
i
=
1
N
w
i
\displaystyle\frac{\sum\limits_{i=1}^N |a_{i} - t_{i}|^q w_i}{\sum\limits_{i=1}^N w_{i}}
Usage information
See
more
.
User-defined parameters
use_weights
Use object/group weights to calculate metrics if the specified value is
true
and set all weights to
1
regardless of the input data if the specified value is
false
.
Default:
true
q
The power coefficient.
Valid values are real numbers in the following range:
[
1
;
+
∞
)
[1; +\infty)
Default:
Obligatory parameter
Huber
L
(
t
,
a
)
=
∑
i
=
0
N
l
(
t
i
,
a
i
)
⋅
w
i
L(t, a) = \sum\limits_{i=0}^N l(t_i, a_i) \cdot w_{i}
l
(
t
,
a
)
=
{
1
2
(
t
−
a
)
2
,
∣
t
−
a
∣
≤
δ
δ
∣
t
−
a
∣
−
1
2
δ
2
,
∣
t
−
a
∣
>
δ
l(t,a) = \begin{cases} \frac{1}{2} (t - a)^{2} { , } & |t -a| \leq \delta \\ \delta|t -a| - \frac{1}{2} \delta^{2} { , } & |t -a| > \delta \end{cases}
User-defined parameters:
delta
The
δ
\delta
parameter of the Huber metric.
Default:
Obligatory parameter
Usage information
See
more
.
User-defined parameters
use_weights
Use object/group weights to calculate metrics if the specified value is
true
and set all weights to
1
regardless of the input data if the specified value is
false
.
Default:
true
Expectile
∑
i
=
1
N
∣
α
−
I
(
t
i
≤
a
i
)
∣
(
t
i
−
a
i
)
2
w
i
∑
i
=
1
N
w
i
\displaystyle\frac{\sum\limits_{i=1}^{N} |\alpha - I(t_{i} \leq a_{i})|(t_{i} - a_{i})^2 w_{i} }{\sum\limits_{i=1}^{N} w_{i}}
Usage information
See
more
.
User-defined parameters
use_weights
Use object/group weights to calculate metrics if the specified value is
true
and set all weights to
1
regardless of the input data if the specified value is
false
.
Default:
true
alpha
The coefficient used in expectile-based losses.
Default:
0.5
Tweedie
∑
i
=
1
N
(
e
a
i
(
2
−
λ
)
2
−
λ
−
t
i
e
a
i
(
1
−
λ
)
1
−
λ
)
⋅
w
i
∑
i
=
1
N
w
i
\displaystyle\frac{\sum\limits_{i=1}^{N}\left(\displaystyle\frac{e^{a_{i}(2-\lambda)}}{2-\lambda} - t_{i}\frac{e^{a_{i}(1-\lambda)}}{1-\lambda} \right)\cdot w_{i}}{\sum\limits_{i=1}^{N} w_{i}}
λ
\lambda
is the value of the variance_power parameter.
Labels
t
i
t_i
should be non-negative.
Large labels may cause numerical overflows and/or divergence when training a tweedie regression model.
On CPU, it is recommended to scale labels to range
[
0
,
1000
]
[0,1000]
.
On GPU, it is recommended to scale lables to range
[
0
,
1
]
[0,1]
.
Usage information
See
more
.
User-defined parameters
use_weights
Use object/group weights to calculate metrics if the specified value is
true
and set all weights to
1
regardless of the input data if the specified value is
false
.
Default:
true
variance_power
The variance of the Tweedie distribution.
Supported values are in the range (1;2).
Default:
Obligatory parameter
LogCosh
∑
i
=
1
N
w
i
log
(
cosh
(
a
i
−
t
i
)
)
∑
i
=
1
N
w
i
\displaystyle\frac{\sum_{i=1}^N w_i \log(\cosh(a_i - t_i))}{\sum_{i=1}^N w_i}
Usage information
See
more
.
User-defined parameters
use_weights
Use object/group weights to calculate metrics if the specified value is
true
and set all weights to
1
regardless of the input data if the specified value is
false
.
Default:
true
FairLoss
∑
i
=
1
N
c
2
(
∣
t
i
−
a
i
∣
c
−
log
(
∣
t
i
−
a
i
∣
c
+
1
)
)
w
i
∑
i
=
1
N
w
i
\displaystyle\frac{\sum\limits_{i=1}^{N} c^2\left(\frac{|t_{i} - a_{i} |}{c} - \log\left(\frac{|t_{i} - a_{i} |}{c} + 1\right)\right)w_{i}}{\sum\limits_{i=1}^{N} w_{i}}
c
c
is the value of the smoothness parameter.
Can't be used for optimization.
See
more
.
User-defined parameters
use_weights
Use object/group weights to calculate metrics if the specified value is
true
and set all weights to
1
regardless of the input data if the specified value is
false
.
Default:
true
use_weights
The smoothness coefficient. Valid values are real values in the following range
(
0
;
+
∞
)
(0; +\infty)
.
Default:
1.0
NumErrors
The proportion of predictions, for which the difference from the label value exceeds the specified value
greater_than
.
∑
i
=
1
N
I
(
∣
a
i
−
t
i
∣
≥
greater_than
)
w
i
∑
i
=
1
N
w
i
\displaystyle\frac{\sum\limits_{i=1}^{N} I(|a_{i} - t_{i}|\geq \text{greater\_than}) w_{i}}{\sum\limits_{i=1}^{N} w_{i}}
User-defined parameters: greater_than
Can't be used for optimization.
See
more
.
User-defined parameters
use_weights
Use object/group weights to calculate metrics if the specified value is
true
and set all weights to
1
regardless of the input data if the specified value is
false
.
Default:
true
SMAPE
100
∑
i
=
1
N
w
i
∣
a
i
−
t
i
∣
(
∣
t
i
∣
+
∣
a
i
∣
)
/
2
∑
i
=
1
N
w
i
\displaystyle\frac{100 \sum\limits_{i=1}^{N}\displaystyle\frac{w_{i} |a_{i} - t_{i} |}{(| t_{i} | + | a_{i} |) / 2}}{\sum\limits_{i=1}^{N} w_{i}}
Can't be used for optimization.
See
more
.
User-defined parameters
use_weights
Use object/group weights to calculate metrics if the specified value is
true
and set all weights to
1
regardless of the input data if the specified value is
false
.
Default:
true
R2
1
−
∑
i
=
1
N
w
i
(
a
i
−
t
i
)
2
∑
i
=
1
N
w
i
(
t
ˉ
−
t
i
)
2
1 - \displaystyle\frac{\sum\limits_{i=1}^{N} w_{i} (a_{i} - t_{i})^{2}}{\sum\limits_{i=1}^{N} w_{i} (\bar{t} - t_{i})^{2}}
t
ˉ
\bar{t}
is the average label value:
t
ˉ
=
1
N
∑
i
=
1
N
t
i
\bar{t} = \frac{1}{N}\sum\limits_{i=1}^{N}t_{i}
Can't be used for optimization.
See
more
.
User-defined parameters
use_weights
Use object/group weights to calculate metrics if the specified value is
true
and set all weights to
1
regardless of the input data if the specified value is
false
.
Default:
true
MSLE
∑
i
=
1
N
w
i
(
log
(
1
+
t
i
)
−
log
(
1
+
a
i
)
)
2
∑
i
=
1
N
w
i
\displaystyle\frac{\sum\limits_{i=1}^{N} w_{i} (\log (1 + t_{i}) - \log (1 + a_{i}))^{2}}{\sum\limits_{i=1}^{N} w_{i}}
Can't be used for optimization.
See
more
.
User-defined parameters
use_weights
Use object/group weights to calculate metrics if the specified value is
true
and set all weights to
1
regardless of the input data if the specified value is
false
.
Default:
true
MedianAbsoluteError
median
(
∣
t
1
−
a
1
∣
,
.
.
.
,
∣
t
N
−
a
N
∣
)
\displaystyle\text{median}(|t_{1} - a_{1}|, ..., |t_{N} - a_{N}|)
Can't be used for optimization.
See
more
.
User-defined parameters
No.
Cox
∑
t
i
>
0
(
a
i
−
log
∑
∣
t
j
∣
≥
t
i
exp
(
a
j
)
)
\displaystyle\sum\limits_{t_i > 0}\left( a_i - \log\sum\limits_{|t_j| \ge t_i} \exp(a_j)\right)
Labels
t
i
>
0
t_i > 0
mean occurence of the event at time
t
i
t_i
, and labels
t
i
<
0
t_i < 0
mean absence of the event at time
∣
t
i
∣
|t_i|
.
Predictions
a
i
a_i
are hazard rates.
Usage information
See
more
.
User-defined parameters
No.
SurvivalAft
∑
t
i
,
0
=
t
i
,
1
log
(
f
(
ϵ
(
t
i
,
0
,
a
i
)
)
+
∑
t
i
,
0
≠
t
i
,
1
log
(
F
(
ϵ
(
t
i
,
1
,
a
i
)
)
−
F
(
ϵ
(
t
i
,
0
,
a
i
)
)
)
\displaystyle\sum\limits_{t_{i,0} = t_{i,1}} \log\left(f(\epsilon(t_{i,0}, a_i)\right) + \sum\limits_{t_{i,0} \ne t_{i,1}} \log \left(F(\epsilon(t_{i,1}, a_i)) - F(\epsilon(t_{i,0}, a_i))\right)
Observation interval is
[
t
i
,
0
,
t
i
,
1
]
[t_{i,0}, t_{i,1}]
for
t
i
,
1
≠
−
1
t_{i,1} \ne -1
, and
[
t
i
,
0
,
∞
)
[t_{i,0}, \infty)
for
t
i
,
1
=
−
1
t_{i,1} = -1
.
Predictions
a
i
a_i
are hazard rates.
Helper
ϵ
(
t
,
a
)
=
(
log
t
−
a
)
/
σ
\epsilon(t, a) = (\log t - a)/\sigma
for
t
≠
−
1
t \ne -1
, and
ϵ
(
−
1
,
a
)
=
∞
\epsilon(-1, a) = \infty
, is hazard prediction error.
Coefficient
σ
\sigma
is scale of hazard prediction error, specified by
scale
parameter.
Functions
f
f
and
F
F
are probability density and cumulative distribution, specified by
dist
parameter.
dist
Guessed distribution of hazard prediction error.
Possible values:
Normal
,
Extreme
,
Logistic
.
dist
F
F
f
f
Normal
1
2
(
1
+
erf
(
z
2
)
)
\displaystyle\frac{1}{2}\left(1+\text{erf}\left( \frac{z}{\sqrt{2}}\right)\right)
e
−
z
2
/
2
2
π
\displaystyle\frac{e^{-z^2/2}}{\sqrt{2\pi}}
Logistic
e
z
1
+
e
z
\displaystyle\frac{e^z}{1+e^z}
e
z
(
1
+
e
z
)
2
\displaystyle\frac{e^z}{(1+e^z)^2}
Extreme
1
−
e
−
e
z
\displaystyle 1-e^{-e^z}
e
z
e
−
e
z
\displaystyle e^ze^{-e^z}
Default:
Normal
scale
Scale of hazard prediction error.
Default:
1.0
Usage information
See
more
.
User-defined parameters
No.
Used for optimization
Name
Optimization
GPU Support
MAE
+
+
MAPE
+
+
Poisson
+
+
Quantile
+
+
MultiQuantile
+
-
RMSE
+
+
RMSEWithUncertainty
+
+
LogLinQuantile
+
+
Lq
+
+
Huber
+
+
Expectile
+
+
Tweedie
+
+
LogCosh
+
-
Cox
+
-
SurvivalAft
+
-
FairLoss
-
-
NumErrors
-
+
SMAPE
-
-
R2
-
-
MSLE
-
-
MedianAbsoluteError
-
- | ||||||||||||||||||
| Markdown | [](https://catboost.ai/ "CatBoost")
- Installation
- [Overview](https://catboost.ai/docs/en/concepts/en/concepts/installation)
- Python package installation
- CatBoost for Apache Spark installation
- R package installation
- Command-line version binary
- Build from source
- Key Features
- Training parameters
- Python package
- CatBoost for Apache Spark
- R package
- Command-line version
- Applying models
- Objectives and metrics
- [Overview](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions)
- [Variables used in formulas](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-variables-used)
- [Regression](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression)
- [Multiregression](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-multiregression)
- [Classification](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-classification)
- [Multiclassification](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-multiclassification)
- [Multilabel Classification](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-multilabel-classification)
- [Ranking](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-ranking)
- Model analysis
- Data format description
- [Parameter tuning](https://catboost.ai/docs/en/concepts/en/concepts/parameter-tuning)
- [Speeding up the training](https://catboost.ai/docs/en/concepts/en/concepts/speed-up-training)
- Data visualization
- Algorithm details
- [FAQ](https://catboost.ai/docs/en/concepts/en/concepts/faq)
- Educational materials
- [Development and contributions](https://catboost.ai/docs/en/concepts/en/concepts/development-and-contributions)
- [Contacts](https://catboost.ai/docs/en/concepts/en/concepts/contacts)
Objectives and metrics
## In this article:
- [Objectives and metrics](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#objectives-and-metrics)
- [MAE](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#MAE)
- [MAPE](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#MAPE)
- [Poisson](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#Poisson)
- [Quantile](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#Quantile)
- [MultiQuantile](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#MultiQuantile)
- [RMSE](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#RMSE)
- [RMSEWithUncertainty](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#RMSEWithUncertainty)
- [LogLinQuantile](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#LogLinQuantile)
- [Lq](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#lq)
- [Huber](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#Huber)
- [Expectile](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#Expectile)
- [Tweedie](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#Tweedie)
- [LogCosh](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#LogCosh)
- [FairLoss](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#FairLoss)
- [NumErrors](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#NumErrors)
- [SMAPE](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#SMAPE)
- [R2](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#R2)
- [MSLE](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#MSLE)
- [MedianAbsoluteError](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#MedianAbsoluteError)
- [Cox](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#Cox)
- [SurvivalAft](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#SurvivalAft)
- [Used for optimization](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#usage-information)
1. [Objectives and metrics](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions)
2. Regression
# Regression: objectives and metrics
- [Objectives and metrics](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#objectives-and-metrics)
- [MAE](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#MAE)
- [MAPE](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#MAPE)
- [Poisson](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#Poisson)
- [Quantile](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#Quantile)
- [MultiQuantile](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#MultiQuantile)
- [RMSE](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#RMSE)
- [RMSEWithUncertainty](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#RMSEWithUncertainty)
- [LogLinQuantile](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#LogLinQuantile)
- [Lq](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#lq)
- [Huber](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#Huber)
- [Expectile](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#Expectile)
- [Tweedie](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#Tweedie)
- [LogCosh](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#LogCosh)
- [FairLoss](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#FairLoss)
- [NumErrors](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#NumErrors)
- [SMAPE](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#SMAPE)
- [R2](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#R2)
- [MSLE](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#MSLE)
- [MedianAbsoluteError](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#MedianAbsoluteError)
- [Cox](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#Cox)
- [SurvivalAft](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#SurvivalAft)
- [Used for optimization](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#usage-information)
- [Objectives and metrics](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#objectives-and-metrics)
- [Used for optimization](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#usage-inforimation)
## Objectives and metrics
### MAE
∑ i \= 1 N w i ∣ a i − t i ∣ ∑ i \= 1 N w i \\displaystyle\\frac{\\sum\\limits\_{i=1}^{N} w\_{i} \| a\_{i} - t\_{i}\| }{\\sum\\limits\_{i=1}^{N} w\_{i}} i\=1∑Nwii\=1∑Nwi∣ai−ti∣
**Usage information** See [more](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
### MAPE
∑ i \= 1 N w i ∣ a i − t i ∣ max ( 1 , ∣ t i ∣ ) ∑ i \= 1 N w i \\displaystyle\\frac{\\sum\\limits\_{i=1}^{N} w\_{i} \\displaystyle\\frac{\|a\_{i}- t\_{i}\|}{\\max(1, \|t\_{i}\|)}}{\\sum\\limits\_{i=1}^{N}w\_{i}} i\=1∑Nwii\=1∑Nwimax(1,∣ti∣)∣ai−ti∣
**Usage information** See [more](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
### Poisson
∑ i \= 1 N w i ( e a i − a i t i ) ∑ i \= 1 N w i \\displaystyle\\frac{\\sum\\limits\_{i=1}^{N} w\_{i} \\left(e^{a\_{i}} - a\_{i}t\_{i}\\right)}{\\sum\\limits\_{i=1}^{N}w\_{i}} i\=1∑Nwii\=1∑Nwi(eai−aiti)
**Usage information** See [more](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
### Quantile
∑ i \= 1 N ( α − I ( t i ≤ a i ) ) ( t i − a i ) w i ∑ i \= 1 N w i \\displaystyle\\frac{\\sum\\limits\_{i=1}^{N} (\\alpha - I(t\_{i} \\leq a\_{i}))(t\_{i} - a\_{i}) w\_{i} }{\\sum\\limits\_{i=1}^{N} w\_{i}} i\=1∑Nwii\=1∑N(α−I(ti≤ai))(ti−ai)wi
**Usage information** See [more](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
alpha
The coefficient used in quantile-based losses.
*Default:* 0.5
### MultiQuantile
∑ i \= 1 N w i ∑ q \= 1 Q ( α q − I ( t i ≤ a i , q ) ) ( t i − a i , q ) ∑ i \= 1 N w i \\displaystyle\\frac{\\sum\\limits\_{i=1}^{N} w\_{i} \\sum\\limits\_{q=1}^{Q} (\\alpha\_{q} - I(t\_{i} \\leq a\_{i,q}))(t\_{i} - a\_{i,q}) }{\\sum\\limits\_{i=1}^{N} w\_{i}} i\=1∑Nwii\=1∑Nwiq\=1∑Q(αq−I(ti≤ai,q))(ti−ai,q)
**Usage information** See [more](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
alpha
The vector of coefficients used in multi-quantile loss.
*Default:* 0.5
### RMSE
∑ i \= 1 N ( a i − t i ) 2 w i ∑ i \= 1 N w i \\displaystyle\\sqrt{\\displaystyle\\frac{\\sum\\limits\_{i=1}^N (a\_{i}-t\_{i})^2 w\_{i}}{\\sum\\limits\_{i=1}^{N}w\_{i}}} i\=1∑Nwii\=1∑N(ai−ti)2wi
**Usage information** See [more](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
### RMSEWithUncertainty
− ∑ i \= 1 N w i log N ( t i ∣ a i , 0 , e 2 a i , 1 ) ∑ i \= 1 N w i \= 1 2 log ( 2 π ) \+ ∑ i \= 1 N w i ( a i , 1 \+ 1 2 e − 2 a i , 1 ( t i − a i , 0 ) 2 ) ∑ i \= 1 N w i \\displaystyle-\\frac{\\sum\_{i=1}^N w\_i \\log N(t\_{i} \\vert a\_{i,0}, e^{2a\_{i,1}})}{\\sum\_{i=1}^{N}w\_{i}} = \\frac{1}{2}\\log(2\\pi) +\\frac{\\sum\_{i=1}^N w\_i\\left(a\_{i,1} + \\frac{1}{2} e^{-2a\_{i,1}}(t\_i - a\_{i, 0})^2 \\right)}{\\sum\_{i=1}^{N}w\_{i}} −∑i\=1Nwi∑i\=1NwilogN(ti∣ai,0,e2ai,1)\=21log(2π)\+∑i\=1Nwi∑i\=1Nwi(ai,1\+21e−2ai,1(ti−ai,0)2),
where t t t is target, a 2-dimensional approx a 0 a\_0 a0 is target predict, a 1 a\_1 a1 is log σ \\log \\sigma logσ predict, and N ( y ∣ μ , σ 2 ) \= 1 2 π σ 2 exp ( − ( y − μ ) 2 2 σ 2 ) N(y\\vert \\mu,\\sigma^2) = \\frac{1}{\\sqrt{2 \\pi\\sigma^2}} \\exp(-\\frac{(y-\\mu)^2}{2\\sigma^2}) N(y∣μ,σ2)\= 2πσ2 1 exp(−2σ2(y−μ)2) is the probability density function of the normal distribution.
See the [Uncertainty section](https://catboost.ai/docs/en/concepts/en/references/uncertainty) for more details.
**Usage information** See [more](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
### LogLinQuantile
Depends on the condition for the ratio of the label value and the resulting value:
{ ∑ i \= 1 N α ∣ t i − e a i ∣ w i ∑ i \= 1 N w i t i \> e a i ∑ i \= 1 N ( 1 − α ) ∣ t i − e a i ∣ w i ∑ i \= 1 N w i t i ≤ e a i \\begin{cases} \\displaystyle\\frac{\\sum\\limits\_{i=1}^{N} \\alpha \|t\_{i} - e^{a\_{i}} \| w\_{i}}{\\sum\\limits\_{i=1}^{N} w\_{i}} & t\_{i} \> e^{a\_{i}} \\\\ \\displaystyle\\frac{\\sum\\limits\_{i=1}^{N} (1 - \\alpha) \|t\_{i} - e^{a\_{i}} \| w\_{i}}{\\sum\\limits\_{i=1}^{N} w\_{i}} & t\_{i} \\leq e^{a\_{i}} \\end{cases} ⎩ ⎨ ⎧ i\=1∑Nwii\=1∑Nα∣ti−eai∣wii\=1∑Nwii\=1∑N(1−α)∣ti−eai∣witi\>eaiti≤eai
**Usage information** See [more](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
alpha
The coefficient used in quantile-based losses.
*Default:* 0.5
### Lq
∑ i \= 1 N ∣ a i − t i ∣ q w i ∑ i \= 1 N w i \\displaystyle\\frac{\\sum\\limits\_{i=1}^N \|a\_{i} - t\_{i}\|^q w\_i}{\\sum\\limits\_{i=1}^N w\_{i}} i\=1∑Nwii\=1∑N∣ai−ti∣qwi
**Usage information** See [more](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
q
The power coefficient.
Valid values are real numbers in the following range: \[ 1 ; \+ ∞ ) \[1; +\\infty) \[1;\+∞)
*Default:* Obligatory parameter
### Huber
L ( t , a ) \= ∑ i \= 0 N l ( t i , a i ) ⋅ w i L(t, a) = \\sum\\limits\_{i=0}^N l(t\_i, a\_i) \\cdot w\_{i} L(t,a)\=i\=0∑Nl(ti,ai)⋅wi
l ( t , a ) \= { 1 2 ( t − a ) 2 , ∣ t − a ∣ ≤ δ δ ∣ t − a ∣ − 1 2 δ 2 , ∣ t − a ∣ \> δ l(t,a) = \\begin{cases} \\frac{1}{2} (t - a)^{2} { , } & \|t -a\| \\leq \\delta \\\\ \\delta\|t -a\| - \\frac{1}{2} \\delta^{2} { , } & \|t -a\| \> \\delta \\end{cases} l(t,a)\={21(t−a)2,δ∣t−a∣−21δ2,∣t−a∣≤δ∣t−a∣\>δ
User-defined parameters:
delta
The δ \\delta δ parameter of the Huber metric.
*Default:* Obligatory parameter
**Usage information** See [more](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
### Expectile
∑ i \= 1 N ∣ α − I ( t i ≤ a i ) ∣ ( t i − a i ) 2 w i ∑ i \= 1 N w i \\displaystyle\\frac{\\sum\\limits\_{i=1}^{N} \|\\alpha - I(t\_{i} \\leq a\_{i})\|(t\_{i} - a\_{i})^2 w\_{i} }{\\sum\\limits\_{i=1}^{N} w\_{i}} i\=1∑Nwii\=1∑N∣α−I(ti≤ai)∣(ti−ai)2wi
**Usage information** See [more](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
alpha
The coefficient used in expectile-based losses.
*Default:* 0.5
### Tweedie
∑ i \= 1 N ( e a i ( 2 − λ ) 2 − λ − t i e a i ( 1 − λ ) 1 − λ ) ⋅ w i ∑ i \= 1 N w i \\displaystyle\\frac{\\sum\\limits\_{i=1}^{N}\\left(\\displaystyle\\frac{e^{a\_{i}(2-\\lambda)}}{2-\\lambda} - t\_{i}\\frac{e^{a\_{i}(1-\\lambda)}}{1-\\lambda} \\right)\\cdot w\_{i}}{\\sum\\limits\_{i=1}^{N} w\_{i}} i\=1∑Nwii\=1∑N(2−λeai(2−λ)−ti1−λeai(1−λ))⋅wi
λ \\lambda λ is the value of the variance\_power parameter.
Labels t i t\_i ti should be non-negative.
Large labels may cause numerical overflows and/or divergence when training a tweedie regression model.
On CPU, it is recommended to scale labels to range \[ 0 , 1000 \] \[0,1000\] \[0,1000\].
On GPU, it is recommended to scale lables to range \[ 0 , 1 \] \[0,1\] \[0,1\].
**Usage information** See [more](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
variance\_power
The variance of the Tweedie distribution.
Supported values are in the range (1;2).
*Default:* Obligatory parameter
### LogCosh
∑ i \= 1 N w i log ( cosh ( a i − t i ) ) ∑ i \= 1 N w i \\displaystyle\\frac{\\sum\_{i=1}^N w\_i \\log(\\cosh(a\_i - t\_i))}{\\sum\_{i=1}^N w\_i} ∑i\=1Nwi∑i\=1Nwilog(cosh(ai−ti))
**Usage information** See [more](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
### FairLoss
∑ i \= 1 N c 2 ( ∣ t i − a i ∣ c − log ( ∣ t i − a i ∣ c \+ 1 ) ) w i ∑ i \= 1 N w i \\displaystyle\\frac{\\sum\\limits\_{i=1}^{N} c^2\\left(\\frac{\|t\_{i} - a\_{i} \|}{c} - \\log\\left(\\frac{\|t\_{i} - a\_{i} \|}{c} + 1\\right)\\right)w\_{i}}{\\sum\\limits\_{i=1}^{N} w\_{i}} i\=1∑Nwii\=1∑Nc2(c∣ti−ai∣−log(c∣ti−ai∣\+1))wi
c c c is the value of the smoothness parameter.
**Can't be used for optimization.** See [more](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
use\_weights
The smoothness coefficient. Valid values are real values in the following range ( 0 ; \+ ∞ ) (0; +\\infty) (0;\+∞).
*Default:* 1.0
### NumErrors
The proportion of predictions, for which the difference from the label value exceeds the specified value `greater_than`.
∑ i \= 1 N I ( ∣ a i − t i ∣ ≥ greater\_than ) w i ∑ i \= 1 N w i \\displaystyle\\frac{\\sum\\limits\_{i=1}^{N} I(\|a\_{i} - t\_{i}\|\\geq \\text{greater\\\_than}) w\_{i}}{\\sum\\limits\_{i=1}^{N} w\_{i}} i\=1∑Nwii\=1∑NI(∣ai−ti∣≥greater\_than)wi
User-defined parameters: greater\_than
**Can't be used for optimization.** See [more](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
### SMAPE
100 ∑ i \= 1 N w i ∣ a i − t i ∣ ( ∣ t i ∣ \+ ∣ a i ∣ ) / 2 ∑ i \= 1 N w i \\displaystyle\\frac{100 \\sum\\limits\_{i=1}^{N}\\displaystyle\\frac{w\_{i} \|a\_{i} - t\_{i} \|}{(\| t\_{i} \| + \| a\_{i} \|) / 2}}{\\sum\\limits\_{i=1}^{N} w\_{i}} i\=1∑Nwi100i\=1∑N(∣ti∣\+∣ai∣)/2wi∣ai−ti∣
**Can't be used for optimization.** See [more](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
### R2
1 − ∑ i \= 1 N w i ( a i − t i ) 2 ∑ i \= 1 N w i ( t ˉ − t i ) 2 1 - \\displaystyle\\frac{\\sum\\limits\_{i=1}^{N} w\_{i} (a\_{i} - t\_{i})^{2}}{\\sum\\limits\_{i=1}^{N} w\_{i} (\\bar{t} - t\_{i})^{2}} 1−i\=1∑Nwi(tˉ−ti)2i\=1∑Nwi(ai−ti)2
t ˉ \\bar{t} tˉ is the average label value:
t ˉ \= 1 N ∑ i \= 1 N t i \\bar{t} = \\frac{1}{N}\\sum\\limits\_{i=1}^{N}t\_{i} tˉ\=N1i\=1∑Nti
**Can't be used for optimization.** See [more](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
### MSLE
∑ i \= 1 N w i ( log ( 1 \+ t i ) − log ( 1 \+ a i ) ) 2 ∑ i \= 1 N w i \\displaystyle\\frac{\\sum\\limits\_{i=1}^{N} w\_{i} (\\log (1 + t\_{i}) - \\log (1 + a\_{i}))^{2}}{\\sum\\limits\_{i=1}^{N} w\_{i}} i\=1∑Nwii\=1∑Nwi(log(1\+ti)−log(1\+ai))2
**Can't be used for optimization.** See [more](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
### MedianAbsoluteError
median ( ∣ t 1 − a 1 ∣ , . . . , ∣ t N − a N ∣ ) \\displaystyle\\text{median}(\|t\_{1} - a\_{1}\|, ..., \|t\_{N} - a\_{N}\|) median(∣t1−a1∣,...,∣tN−aN∣)
**Can't be used for optimization.** See [more](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
No.
### Cox
∑ t i \> 0 ( a i − log ∑ ∣ t j ∣ ≥ t i exp ( a j ) ) \\displaystyle\\sum\\limits\_{t\_i \> 0}\\left( a\_i - \\log\\sum\\limits\_{\|t\_j\| \\ge t\_i} \\exp(a\_j)\\right) ti\>0∑ ai−log∣tj∣≥ti∑exp(aj)
Labels t i \> 0 t\_i \> 0 ti\>0 mean occurence of the event at time t i t\_i ti, and labels t i \< 0 t\_i \< 0 ti\<0 mean absence of the event at time ∣ t i ∣ \|t\_i\| ∣ti∣.
Predictions a i a\_i ai are hazard rates.
**Usage information** See [more](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
No.
### SurvivalAft
∑ t i , 0 \= t i , 1 log ( f ( ϵ ( t i , 0 , a i ) ) \+ ∑ t i , 0 ≠ t i , 1 log ( F ( ϵ ( t i , 1 , a i ) ) − F ( ϵ ( t i , 0 , a i ) ) ) \\displaystyle\\sum\\limits\_{t\_{i,0} = t\_{i,1}} \\log\\left(f(\\epsilon(t\_{i,0}, a\_i)\\right) + \\sum\\limits\_{t\_{i,0} \\ne t\_{i,1}} \\log \\left(F(\\epsilon(t\_{i,1}, a\_i)) - F(\\epsilon(t\_{i,0}, a\_i))\\right) ti,0\=ti,1∑log(f(ϵ(ti,0,ai))\+ti,0\=ti,1∑log(F(ϵ(ti,1,ai))−F(ϵ(ti,0,ai)))
Observation interval is \[ t i , 0 , t i , 1 \] \[t\_{i,0}, t\_{i,1}\] \[ti,0,ti,1\] for t i , 1 ≠ − 1 t\_{i,1} \\ne -1 ti,1\=−1, and \[ t i , 0 , ∞ ) \[t\_{i,0}, \\infty) \[ti,0,∞) for t i , 1 \= − 1 t\_{i,1} = -1 ti,1\=−1.
Predictions a i a\_i ai are hazard rates.
Helper ϵ ( t , a ) \= ( log t − a ) / σ \\epsilon(t, a) = (\\log t - a)/\\sigma ϵ(t,a)\=(logt−a)/σ for t ≠ − 1 t \\ne -1 t\=−1, and ϵ ( − 1 , a ) \= ∞ \\epsilon(-1, a) = \\infty ϵ(−1,a)\=∞, is hazard prediction error.
Coefficient σ \\sigma σ is scale of hazard prediction error, specified by `scale` parameter.
Functions f f f and F F F are probability density and cumulative distribution, specified by `dist` parameter.
dist
Guessed distribution of hazard prediction error.
Possible values: `Normal`, `Extreme`, `Logistic`.
| `dist` | F F F | f f f |
|---|---|---|
| `Normal` | 1 2 ( 1 \+ erf ( z 2 ) ) \\displaystyle\\frac{1}{2}\\left(1+\\text{erf}\\left( \\frac{z}{\\sqrt{2}}\\right)\\right) 21 (1\+erf ( 2 z ) ) | e − z 2 / 2 2 π \\displaystyle\\frac{e^{-z^2/2}}{\\sqrt{2\\pi}} 2π e−z2/2 |
| `Logistic` | e z 1 \+ e z \\displaystyle\\frac{e^z}{1+e^z} 1\+ezez | e z ( 1 \+ e z ) 2 \\displaystyle\\frac{e^z}{(1+e^z)^2} (1\+ez)2ez |
| `Extreme` | 1 − e − e z \\displaystyle 1-e^{-e^z} 1−e−ez | e z e − e z \\displaystyle e^ze^{-e^z} eze−ez |
*Default:* `Normal`
scale
Scale of hazard prediction error.
*Default:* 1.0
**Usage information** See [more](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
No.
## Used for optimization
| Name | Optimization | GPU Support |
|---|---|---|
| [MAE](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#MAE) | \+ | \+ |
| [MAPE](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#MAPE) | \+ | \+ |
| [Poisson](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#Poisson) | \+ | \+ |
| [Quantile](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#Quantile) | \+ | \+ |
| [MultiQuantile](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#MultiQuantile) | \+ | \- |
| [RMSE](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#RMSE) | \+ | \+ |
| [RMSEWithUncertainty](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#RMSEWithUncertainty) | \+ | \+ |
| [LogLinQuantile](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#LogLinQuantile) | \+ | \+ |
| [Lq](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#lq) | \+ | \+ |
| [Huber](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#Huber) | \+ | \+ |
| [Expectile](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#Expectile) | \+ | \+ |
| [Tweedie](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#Tweedie) | \+ | \+ |
| [LogCosh](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#LogCosh) | \+ | \- |
| [Cox](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#Cox) | \+ | \- |
| [SurvivalAft](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#SurvivalAft) | \+ | \- |
| [FairLoss](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#FairLoss) | \- | \- |
| [NumErrors](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#NumErrors) | \- | \+ |
| [SMAPE](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#SMAPE) | \- | \- |
| [R2](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#R2) | \- | \- |
| [MSLE](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#MSLE) | \- | \- |
| [MedianAbsoluteError](https://catboost.ai/docs/en/concepts/en/concepts/loss-functions-regression#MedianAbsoluteError) | \- | \- |
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| Readable Markdown | - [Objectives and metrics](https://catboost.ai/docs/en/concepts/loss-functions-regression#objectives-and-metrics)
- [Used for optimization](https://catboost.ai/docs/en/concepts/loss-functions-regression#usage-inforimation)
## Objectives and metrics
### MAE
∑ i \= 1 N w i ∣ a i − t i ∣ ∑ i \= 1 N w i \\displaystyle\\frac{\\sum\\limits\_{i=1}^{N} w\_{i} \| a\_{i} - t\_{i}\| }{\\sum\\limits\_{i=1}^{N} w\_{i}}
**Usage information** See [more](https://catboost.ai/docs/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
### MAPE
∑ i \= 1 N w i ∣ a i − t i ∣ max ( 1 , ∣ t i ∣ ) ∑ i \= 1 N w i \\displaystyle\\frac{\\sum\\limits\_{i=1}^{N} w\_{i} \\displaystyle\\frac{\|a\_{i}- t\_{i}\|}{\\max(1, \|t\_{i}\|)}}{\\sum\\limits\_{i=1}^{N}w\_{i}}
**Usage information** See [more](https://catboost.ai/docs/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
### Poisson
∑ i \= 1 N w i ( e a i − a i t i ) ∑ i \= 1 N w i \\displaystyle\\frac{\\sum\\limits\_{i=1}^{N} w\_{i} \\left(e^{a\_{i}} - a\_{i}t\_{i}\\right)}{\\sum\\limits\_{i=1}^{N}w\_{i}}
**Usage information** See [more](https://catboost.ai/docs/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
### Quantile
∑ i \= 1 N ( α − I ( t i ≤ a i ) ) ( t i − a i ) w i ∑ i \= 1 N w i \\displaystyle\\frac{\\sum\\limits\_{i=1}^{N} (\\alpha - I(t\_{i} \\leq a\_{i}))(t\_{i} - a\_{i}) w\_{i} }{\\sum\\limits\_{i=1}^{N} w\_{i}}
**Usage information** See [more](https://catboost.ai/docs/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
alpha
The coefficient used in quantile-based losses.
*Default:* 0.5
### MultiQuantile
∑ i \= 1 N w i ∑ q \= 1 Q ( α q − I ( t i ≤ a i , q ) ) ( t i − a i , q ) ∑ i \= 1 N w i \\displaystyle\\frac{\\sum\\limits\_{i=1}^{N} w\_{i} \\sum\\limits\_{q=1}^{Q} (\\alpha\_{q} - I(t\_{i} \\leq a\_{i,q}))(t\_{i} - a\_{i,q}) }{\\sum\\limits\_{i=1}^{N} w\_{i}}
**Usage information** See [more](https://catboost.ai/docs/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
alpha
The vector of coefficients used in multi-quantile loss.
*Default:* 0.5
### RMSE
∑ i \= 1 N ( a i − t i ) 2 w i ∑ i \= 1 N w i \\displaystyle\\sqrt{\\displaystyle\\frac{\\sum\\limits\_{i=1}^N (a\_{i}-t\_{i})^2 w\_{i}}{\\sum\\limits\_{i=1}^{N}w\_{i}}}
**Usage information** See [more](https://catboost.ai/docs/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
### RMSEWithUncertainty
− ∑ i \= 1 N w i log N ( t i ∣ a i , 0 , e 2 a i , 1 ) ∑ i \= 1 N w i \= 1 2 log ( 2 π ) \+ ∑ i \= 1 N w i ( a i , 1 \+ 1 2 e − 2 a i , 1 ( t i − a i , 0 ) 2 ) ∑ i \= 1 N w i \\displaystyle-\\frac{\\sum\_{i=1}^N w\_i \\log N(t\_{i} \\vert a\_{i,0}, e^{2a\_{i,1}})}{\\sum\_{i=1}^{N}w\_{i}} = \\frac{1}{2}\\log(2\\pi) +\\frac{\\sum\_{i=1}^N w\_i\\left(a\_{i,1} + \\frac{1}{2} e^{-2a\_{i,1}}(t\_i - a\_{i, 0})^2 \\right)}{\\sum\_{i=1}^{N}w\_{i}},
where t t is target, a 2-dimensional approx a 0 a\_0 is target predict, a 1 a\_1 is log σ \\log \\sigma predict, and N ( y ∣ μ , σ 2 ) \= 1 2 π σ 2 exp ( − ( y − μ ) 2 2 σ 2 ) N(y\\vert \\mu,\\sigma^2) = \\frac{1}{\\sqrt{2 \\pi\\sigma^2}} \\exp(-\\frac{(y-\\mu)^2}{2\\sigma^2}) is the probability density function of the normal distribution.
See the [Uncertainty section](https://catboost.ai/docs/en/references/uncertainty) for more details.
**Usage information** See [more](https://catboost.ai/docs/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
### LogLinQuantile
Depends on the condition for the ratio of the label value and the resulting value:
{ ∑ i \= 1 N α ∣ t i − e a i ∣ w i ∑ i \= 1 N w i t i \> e a i ∑ i \= 1 N ( 1 − α ) ∣ t i − e a i ∣ w i ∑ i \= 1 N w i t i ≤ e a i \\begin{cases} \\displaystyle\\frac{\\sum\\limits\_{i=1}^{N} \\alpha \|t\_{i} - e^{a\_{i}} \| w\_{i}}{\\sum\\limits\_{i=1}^{N} w\_{i}} & t\_{i} \> e^{a\_{i}} \\\\ \\displaystyle\\frac{\\sum\\limits\_{i=1}^{N} (1 - \\alpha) \|t\_{i} - e^{a\_{i}} \| w\_{i}}{\\sum\\limits\_{i=1}^{N} w\_{i}} & t\_{i} \\leq e^{a\_{i}} \\end{cases}
**Usage information** See [more](https://catboost.ai/docs/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
alpha
The coefficient used in quantile-based losses.
*Default:* 0.5
### Lq
∑ i \= 1 N ∣ a i − t i ∣ q w i ∑ i \= 1 N w i \\displaystyle\\frac{\\sum\\limits\_{i=1}^N \|a\_{i} - t\_{i}\|^q w\_i}{\\sum\\limits\_{i=1}^N w\_{i}}
**Usage information** See [more](https://catboost.ai/docs/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
q
The power coefficient.
Valid values are real numbers in the following range: \[ 1 ; \+ ∞ ) \[1; +\\infty)
*Default:* Obligatory parameter
### Huber
L ( t , a ) \= ∑ i \= 0 N l ( t i , a i ) ⋅ w i L(t, a) = \\sum\\limits\_{i=0}^N l(t\_i, a\_i) \\cdot w\_{i}
l ( t , a ) \= { 1 2 ( t − a ) 2 , ∣ t − a ∣ ≤ δ δ ∣ t − a ∣ − 1 2 δ 2 , ∣ t − a ∣ \> δ l(t,a) = \\begin{cases} \\frac{1}{2} (t - a)^{2} { , } & \|t -a\| \\leq \\delta \\\\ \\delta\|t -a\| - \\frac{1}{2} \\delta^{2} { , } & \|t -a\| \> \\delta \\end{cases}
User-defined parameters:
delta
The δ \\delta parameter of the Huber metric.
*Default:* Obligatory parameter
**Usage information** See [more](https://catboost.ai/docs/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
### Expectile
∑ i \= 1 N ∣ α − I ( t i ≤ a i ) ∣ ( t i − a i ) 2 w i ∑ i \= 1 N w i \\displaystyle\\frac{\\sum\\limits\_{i=1}^{N} \|\\alpha - I(t\_{i} \\leq a\_{i})\|(t\_{i} - a\_{i})^2 w\_{i} }{\\sum\\limits\_{i=1}^{N} w\_{i}}
**Usage information** See [more](https://catboost.ai/docs/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
alpha
The coefficient used in expectile-based losses.
*Default:* 0.5
### Tweedie
∑ i \= 1 N ( e a i ( 2 − λ ) 2 − λ − t i e a i ( 1 − λ ) 1 − λ ) ⋅ w i ∑ i \= 1 N w i \\displaystyle\\frac{\\sum\\limits\_{i=1}^{N}\\left(\\displaystyle\\frac{e^{a\_{i}(2-\\lambda)}}{2-\\lambda} - t\_{i}\\frac{e^{a\_{i}(1-\\lambda)}}{1-\\lambda} \\right)\\cdot w\_{i}}{\\sum\\limits\_{i=1}^{N} w\_{i}}
λ \\lambda is the value of the variance\_power parameter.
Labels t i t\_i should be non-negative.
Large labels may cause numerical overflows and/or divergence when training a tweedie regression model.
On CPU, it is recommended to scale labels to range \[ 0 , 1000 \] \[0,1000\].
On GPU, it is recommended to scale lables to range \[ 0 , 1 \] \[0,1\].
**Usage information** See [more](https://catboost.ai/docs/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
variance\_power
The variance of the Tweedie distribution.
Supported values are in the range (1;2).
*Default:* Obligatory parameter
### LogCosh
∑ i \= 1 N w i log ( cosh ( a i − t i ) ) ∑ i \= 1 N w i \\displaystyle\\frac{\\sum\_{i=1}^N w\_i \\log(\\cosh(a\_i - t\_i))}{\\sum\_{i=1}^N w\_i}
**Usage information** See [more](https://catboost.ai/docs/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
### FairLoss
∑ i \= 1 N c 2 ( ∣ t i − a i ∣ c − log ( ∣ t i − a i ∣ c \+ 1 ) ) w i ∑ i \= 1 N w i \\displaystyle\\frac{\\sum\\limits\_{i=1}^{N} c^2\\left(\\frac{\|t\_{i} - a\_{i} \|}{c} - \\log\\left(\\frac{\|t\_{i} - a\_{i} \|}{c} + 1\\right)\\right)w\_{i}}{\\sum\\limits\_{i=1}^{N} w\_{i}}
c c is the value of the smoothness parameter.
**Can't be used for optimization.** See [more](https://catboost.ai/docs/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
use\_weights
The smoothness coefficient. Valid values are real values in the following range ( 0 ; \+ ∞ ) (0; +\\infty).
*Default:* 1.0
### NumErrors
The proportion of predictions, for which the difference from the label value exceeds the specified value `greater_than`.
∑ i \= 1 N I ( ∣ a i − t i ∣ ≥ greater\_than ) w i ∑ i \= 1 N w i \\displaystyle\\frac{\\sum\\limits\_{i=1}^{N} I(\|a\_{i} - t\_{i}\|\\geq \\text{greater\\\_than}) w\_{i}}{\\sum\\limits\_{i=1}^{N} w\_{i}}
User-defined parameters: greater\_than
**Can't be used for optimization.** See [more](https://catboost.ai/docs/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
### SMAPE
100 ∑ i \= 1 N w i ∣ a i − t i ∣ ( ∣ t i ∣ \+ ∣ a i ∣ ) / 2 ∑ i \= 1 N w i \\displaystyle\\frac{100 \\sum\\limits\_{i=1}^{N}\\displaystyle\\frac{w\_{i} \|a\_{i} - t\_{i} \|}{(\| t\_{i} \| + \| a\_{i} \|) / 2}}{\\sum\\limits\_{i=1}^{N} w\_{i}}
**Can't be used for optimization.** See [more](https://catboost.ai/docs/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
### R2
1 − ∑ i \= 1 N w i ( a i − t i ) 2 ∑ i \= 1 N w i ( t ˉ − t i ) 2 1 - \\displaystyle\\frac{\\sum\\limits\_{i=1}^{N} w\_{i} (a\_{i} - t\_{i})^{2}}{\\sum\\limits\_{i=1}^{N} w\_{i} (\\bar{t} - t\_{i})^{2}}
t ˉ \\bar{t} is the average label value:
t ˉ \= 1 N ∑ i \= 1 N t i \\bar{t} = \\frac{1}{N}\\sum\\limits\_{i=1}^{N}t\_{i}
**Can't be used for optimization.** See [more](https://catboost.ai/docs/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
### MSLE
∑ i \= 1 N w i ( log ( 1 \+ t i ) − log ( 1 \+ a i ) ) 2 ∑ i \= 1 N w i \\displaystyle\\frac{\\sum\\limits\_{i=1}^{N} w\_{i} (\\log (1 + t\_{i}) - \\log (1 + a\_{i}))^{2}}{\\sum\\limits\_{i=1}^{N} w\_{i}}
**Can't be used for optimization.** See [more](https://catboost.ai/docs/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
use\_weights
Use object/group weights to calculate metrics if the specified value is "true" and set all weights to "1" regardless of the input data if the specified value is "false".
*Default:* true
### MedianAbsoluteError
median ( ∣ t 1 − a 1 ∣ , . . . , ∣ t N − a N ∣ ) \\displaystyle\\text{median}(\|t\_{1} - a\_{1}\|, ..., \|t\_{N} - a\_{N}\|)
**Can't be used for optimization.** See [more](https://catboost.ai/docs/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
No.
### Cox
∑ t i \> 0 ( a i − log ∑ ∣ t j ∣ ≥ t i exp ( a j ) ) \\displaystyle\\sum\\limits\_{t\_i \> 0}\\left( a\_i - \\log\\sum\\limits\_{\|t\_j\| \\ge t\_i} \\exp(a\_j)\\right)
Labels t i \> 0 t\_i \> 0 mean occurence of the event at time t i t\_i, and labels t i \< 0 t\_i \< 0 mean absence of the event at time ∣ t i ∣ \|t\_i\|.
Predictions a i a\_i are hazard rates.
**Usage information** See [more](https://catboost.ai/docs/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
No.
### SurvivalAft
∑ t i , 0 \= t i , 1 log ( f ( ϵ ( t i , 0 , a i ) ) \+ ∑ t i , 0 ≠ t i , 1 log ( F ( ϵ ( t i , 1 , a i ) ) − F ( ϵ ( t i , 0 , a i ) ) ) \\displaystyle\\sum\\limits\_{t\_{i,0} = t\_{i,1}} \\log\\left(f(\\epsilon(t\_{i,0}, a\_i)\\right) + \\sum\\limits\_{t\_{i,0} \\ne t\_{i,1}} \\log \\left(F(\\epsilon(t\_{i,1}, a\_i)) - F(\\epsilon(t\_{i,0}, a\_i))\\right)
Observation interval is \[ t i , 0 , t i , 1 \] \[t\_{i,0}, t\_{i,1}\] for t i , 1 ≠ − 1 t\_{i,1} \\ne -1, and \[ t i , 0 , ∞ ) \[t\_{i,0}, \\infty) for t i , 1 \= − 1 t\_{i,1} = -1.
Predictions a i a\_i are hazard rates.
Helper ϵ ( t , a ) \= ( log t − a ) / σ \\epsilon(t, a) = (\\log t - a)/\\sigma for t ≠ − 1 t \\ne -1, and ϵ ( − 1 , a ) \= ∞ \\epsilon(-1, a) = \\infty, is hazard prediction error.
Coefficient σ \\sigma is scale of hazard prediction error, specified by `scale` parameter.
Functions f f and F F are probability density and cumulative distribution, specified by `dist` parameter.
dist
Guessed distribution of hazard prediction error.
Possible values: `Normal`, `Extreme`, `Logistic`.
| `dist` | F F | f f |
|---|---|---|
| `Normal` | 1 2 ( 1 \+ erf ( z 2 ) ) \\displaystyle\\frac{1}{2}\\left(1+\\text{erf}\\left( \\frac{z}{\\sqrt{2}}\\right)\\right) | e − z 2 / 2 2 π \\displaystyle\\frac{e^{-z^2/2}}{\\sqrt{2\\pi}} |
| `Logistic` | e z 1 \+ e z \\displaystyle\\frac{e^z}{1+e^z} | e z ( 1 \+ e z ) 2 \\displaystyle\\frac{e^z}{(1+e^z)^2} |
| `Extreme` | 1 − e − e z \\displaystyle 1-e^{-e^z} | e z e − e z \\displaystyle e^ze^{-e^z} |
*Default:* `Normal`
scale
Scale of hazard prediction error.
*Default:* 1.0
**Usage information** See [more](https://catboost.ai/docs/en/concepts/loss-functions-regression#usage-information).
**User-defined parameters**
No.
## Used for optimization
| Name | Optimization | GPU Support |
|---|---|---|
| [MAE](https://catboost.ai/docs/en/concepts/loss-functions-regression#MAE) | \+ | \+ |
| [MAPE](https://catboost.ai/docs/en/concepts/loss-functions-regression#MAPE) | \+ | \+ |
| [Poisson](https://catboost.ai/docs/en/concepts/loss-functions-regression#Poisson) | \+ | \+ |
| [Quantile](https://catboost.ai/docs/en/concepts/loss-functions-regression#Quantile) | \+ | \+ |
| [MultiQuantile](https://catboost.ai/docs/en/concepts/loss-functions-regression#MultiQuantile) | \+ | \- |
| [RMSE](https://catboost.ai/docs/en/concepts/loss-functions-regression#RMSE) | \+ | \+ |
| [RMSEWithUncertainty](https://catboost.ai/docs/en/concepts/loss-functions-regression#RMSEWithUncertainty) | \+ | \+ |
| [LogLinQuantile](https://catboost.ai/docs/en/concepts/loss-functions-regression#LogLinQuantile) | \+ | \+ |
| [Lq](https://catboost.ai/docs/en/concepts/loss-functions-regression#lq) | \+ | \+ |
| [Huber](https://catboost.ai/docs/en/concepts/loss-functions-regression#Huber) | \+ | \+ |
| [Expectile](https://catboost.ai/docs/en/concepts/loss-functions-regression#Expectile) | \+ | \+ |
| [Tweedie](https://catboost.ai/docs/en/concepts/loss-functions-regression#Tweedie) | \+ | \+ |
| [LogCosh](https://catboost.ai/docs/en/concepts/loss-functions-regression#LogCosh) | \+ | \- |
| [Cox](https://catboost.ai/docs/en/concepts/loss-functions-regression#Cox) | \+ | \- |
| [SurvivalAft](https://catboost.ai/docs/en/concepts/loss-functions-regression#SurvivalAft) | \+ | \- |
| [FairLoss](https://catboost.ai/docs/en/concepts/loss-functions-regression#FairLoss) | \- | \- |
| [NumErrors](https://catboost.ai/docs/en/concepts/loss-functions-regression#NumErrors) | \- | \+ |
| [SMAPE](https://catboost.ai/docs/en/concepts/loss-functions-regression#SMAPE) | \- | \- |
| [R2](https://catboost.ai/docs/en/concepts/loss-functions-regression#R2) | \- | \- |
| [MSLE](https://catboost.ai/docs/en/concepts/loss-functions-regression#MSLE) | \- | \- |
| [MedianAbsoluteError](https://catboost.ai/docs/en/concepts/loss-functions-regression#MedianAbsoluteError) | \- | \- | | ||||||||||||||||||
| ML Classification | |||||||||||||||||||
| ML Categories |
Raw JSON{
"/Science": 670,
"/Science/Mathematics": 636,
"/Science/Mathematics/Statistics": 618,
"/Computers_and_Electronics": 308,
"/Computers_and_Electronics/Software": 295,
"/Computers_and_Electronics/Software/Educational_Software": 186
} | ||||||||||||||||||
| ML Page Types |
Raw JSON{
"/Article": 885,
"/Article/Tutorial_or_Guide": 789
} | ||||||||||||||||||
| ML Intent Types |
Raw JSON{
"Informational": 999
} | ||||||||||||||||||
| Content Metadata | |||||||||||||||||||
| Language | en | ||||||||||||||||||
| Author | null | ||||||||||||||||||
| Publish Time | not set | ||||||||||||||||||
| Original Publish Time | 2024-11-20 00:02:18 (1 year ago) | ||||||||||||||||||
| Republished | No | ||||||||||||||||||
| Word Count (Total) | 3,888 | ||||||||||||||||||
| Word Count (Content) | 2,506 | ||||||||||||||||||
| Links | |||||||||||||||||||
| External Links | 0 | ||||||||||||||||||
| Internal Links | 18 | ||||||||||||||||||
| Technical SEO | |||||||||||||||||||
| Meta Nofollow | No | ||||||||||||||||||
| Meta Noarchive | No | ||||||||||||||||||
| JS Rendered | Yes | ||||||||||||||||||
| Redirect Target | null | ||||||||||||||||||
| Performance | |||||||||||||||||||
| Download Time (ms) | 731 | ||||||||||||||||||
| TTFB (ms) | 464 | ||||||||||||||||||
| Download Size (bytes) | 864,392 | ||||||||||||||||||
| Shard | 169 (laksa) | ||||||||||||||||||
| Root Hash | 17435841955170310369 | ||||||||||||||||||
| Unparsed URL | ai,catboost!/docs/en/concepts/loss-functions-regression s443 | ||||||||||||||||||