metrax.MSE

class metrax.MSE(total: Array, count: Array)

Bases: Average

Computes the mean squared error for regression problems given predictions and labels.

The mean squared error without sample weights is defined as:

\[MSE = \frac{1}{N} \sum_{i=1}^{N} (y_i - \hat{y}_i)^2\]

When sample weights \(w_i\) are provided, the weighted mean squared error is:

\[MSE = \frac{\sum_{i=1}^{N} w_i(y_i - \hat{y}_i)^2}{\sum_{i=1}^{N} w_i}\]

where:

• \(y_i\) are true values

• \(\hat{y}_i\) are predictions

• \(w_i\) are sample weights

• \(N\) is the number of samples

__init__(total: Array, count: Array) → None

Methods

__init__(total, count)
compute()	Computes final metrics from intermediate values.
compute_value()	Wraps compute() and returns a values.Value.
empty()	Returns an empty instance (i.e. .merge(Metric.empty()) is a no-op).
from_fun(fun)	Calls cls.from_model_output with the return value from fun.
from_model_output(predictions, labels[, ...])	Updates the metric.
from_output(name)	Calls cls.from_model_output with model output named name.
merge(other)	Returns Metric that is the accumulation of self and other.
reduce()	Reduces the metric along it first axis by calling _reduce_merge().
replace(**updates)	Returns a new object replacing the specified fields with new values.

Attributes

total
count

classmethod from_model_output(predictions: Array, labels: Array, sample_weights: Array | None = None) → MSE

Updates the metric.

Parameters:

• predictions – A floating point 1D vector representing the prediction generated from the model. The shape should be (batch_size,).

• labels – True value. The shape should be (batch_size,).

• sample_weights – An optional floating point 1D vector representing the weight of each sample. The shape should be (batch_size,).

Returns:

Updated MSE metric. The shape should be a single scalar.

Raises:

• ValueError – If type of labels is wrong or the shapes of predictions

• and labels are incompatible. –

__init__(total: Array, count: Array) → None

replace(**updates)

Returns a new object replacing the specified fields with new values.