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Overview

Regression metrics evaluate the performance of regression models by comparing predicted values to true values.

Functions

mse

Calculate Mean Squared Error (MSE).
function mse(yTrue: Tensor, yPred: Tensor): number
yTrue
Tensor
required
Ground truth (correct) target values
yPred
Tensor
required
Estimated target values
Returns
number
MSE value (always non-negative, 0 is perfect)
Measures the average squared difference between predictions and actual values. Formula: MSE = (1/n) * Σ(y_true - y_pred)² Example:
import { mse, tensor } from 'deepbox/metrics';

const yTrue = tensor([3, -0.5, 2, 7]);
const yPred = tensor([2.5, 0.0, 2, 8]);
const error = mse(yTrue, yPred);  // 0.375

rmse

Calculate Root Mean Squared Error (RMSE).
function rmse(yTrue: Tensor, yPred: Tensor): number
yTrue
Tensor
required
Ground truth (correct) target values
yPred
Tensor
required
Estimated target values
Returns
number
RMSE value (always non-negative, 0 is perfect)
Square root of MSE, expressed in the same units as the target variable. Example:
import { rmse, tensor } from 'deepbox/metrics';

const yTrue = tensor([3, -0.5, 2, 7]);
const yPred = tensor([2.5, 0.0, 2, 8]);
const error = rmse(yTrue, yPred);  // √0.375 ≈ 0.612

mae

Calculate Mean Absolute Error (MAE).
function mae(yTrue: Tensor, yPred: Tensor): number
yTrue
Tensor
required
Ground truth (correct) target values
yPred
Tensor
required
Estimated target values
Returns
number
MAE value (always non-negative, 0 is perfect)
Measures the average absolute difference between predictions and actual values. Formula: MAE = (1/n) * Σ|y_true - y_pred| Example:
import { mae, tensor } from 'deepbox/metrics';

const yTrue = tensor([3, -0.5, 2, 7]);
const yPred = tensor([2.5, 0.0, 2, 8]);
const error = mae(yTrue, yPred);  // 0.5

r2Score

Calculate R² (coefficient of determination) score.
function r2Score(yTrue: Tensor, yPred: Tensor): number
yTrue
Tensor
required
Ground truth (correct) target values
yPred
Tensor
required
Estimated target values
Returns
number
R² score (1 is perfect, 0 is baseline, negative is worse than baseline)
Represents the proportion of variance in the target variable that is explained by the model. Example:
import { r2Score, tensor } from 'deepbox/metrics';

const yTrue = tensor([3, -0.5, 2, 7]);
const yPred = tensor([2.5, 0.0, 2, 8]);
const score = r2Score(yTrue, yPred);  // Close to 1 for good fit

adjustedR2Score

Calculate Adjusted R² score.
function adjustedR2Score(yTrue: Tensor, yPred: Tensor, nFeatures: number): number
yTrue
Tensor
required
Ground truth (correct) target values
yPred
Tensor
required
Estimated target values
nFeatures
number
required
Number of features (predictors) used in the model
Returns
number
Adjusted R² score
R² adjusted for the number of features in the model. Formula: Adjusted R² = 1 - ((1 - R²) * (n - 1)) / (n - p - 1) Example:
import { adjustedR2Score, tensor } from 'deepbox/metrics';

const yTrue = tensor([3, -0.5, 2, 7]);
const yPred = tensor([2.5, 0.0, 2, 8]);
const score = adjustedR2Score(yTrue, yPred, 2);  // Adjusted for 2 features

mape

Calculate Mean Absolute Percentage Error (MAPE).
function mape(yTrue: Tensor, yPred: Tensor): number
yTrue
Tensor
required
Ground truth (correct) target values
yPred
Tensor
required
Estimated target values
Returns
number
MAPE value as percentage (0 is perfect, lower is better)
Measures the average absolute percentage difference between predictions and actual values. Zero values in yTrue are skipped. Example:
import { mape, tensor } from 'deepbox/metrics';

const yTrue = tensor([3, -0.5, 2, 7]);
const yPred = tensor([2.5, 0.0, 2, 8]);
const error = mape(yTrue, yPred);  // Percentage error

medianAbsoluteError

Calculate Median Absolute Error (MedAE).
function medianAbsoluteError(yTrue: Tensor, yPred: Tensor): number
yTrue
Tensor
required
Ground truth (correct) target values
yPred
Tensor
required
Estimated target values
Returns
number
Median absolute error (always non-negative, 0 is perfect)
Measures the median of absolute differences. More robust to outliers than MAE or MSE.

maxError

Calculate maximum residual error.
function maxError(yTrue: Tensor, yPred: Tensor): number
yTrue
Tensor
required
Ground truth (correct) target values
yPred
Tensor
required
Estimated target values
Returns
number
Maximum absolute error (always non-negative, 0 is perfect)
Returns the maximum absolute difference between predictions and actual values. Example:
import { maxError, tensor } from 'deepbox/metrics';

const yTrue = tensor([3, -0.5, 2, 7]);
const yPred = tensor([2.5, 0.0, 2, 8]);
const error = maxError(yTrue, yPred);  // 1.0 (worst prediction)

explainedVarianceScore

Calculate explained variance score.
function explainedVarianceScore(yTrue: Tensor, yPred: Tensor): number
yTrue
Tensor
required
Ground truth (correct) target values
yPred
Tensor
required
Estimated target values
Returns
number
Explained variance score (1.0 is perfect, lower is worse)
Measures the proportion of variance in the target variable that is explained by the model. Similar to R² but uses variance instead of sum of squares.

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