Metrics calibrationcurve compute

Development build. This page describes main, not a released package. The latest published Lodestar.Metrics is 0.3.0 — read its documentation.

CalibrationCurve.Compute

Draws the reliability curve — sklearn.calibration.calibration_curve.

public static CalibrationCurve Compute(ReadOnlySpan<int> yTrue, ReadOnlySpan<double> yProb, int posLabel = 1, int nBins = 5, BinStrategy strategy = BinStrategy.Uniform)

Parameters — yTrue is the true labels, one per sample, naming at most two classes. yProb is a predicted probability per sample, each within [0, 1]. posLabel is the label counted as positive, 1 by default where the reference infers it. nBins is how many bins to cut [0, 1] into, 5 by default. strategy is where the edges come from — see the type page for what the two divide.

Returns — a CalibrationCurve whose ProbTrue and ProbPred share a length that is at most nBins: a bin no sample fell into is dropped.

Exceptions — ArgumentException when the inputs disagree in length, are empty, carry a probability outside [0, 1], or name more than two classes. ArgumentOutOfRangeException when nBins is below 1.

Example — four probabilities over five bins, one of which nothing falls into.

using Lodestar.Metrics;

int[] truth = [0, 1, 1, 0];
double[] probabilities = [0.1, 0.9, 0.8, 0.3];

CalibrationCurve curve = CalibrationCurve.Compute(truth, probabilities);
int points = curve.ProbTrue.Count;   // => 4

Remarks — there is no sampleWeight: the reference has none for this curve, where BrierScore.Score and LogLoss.Score both take one. BinStrategy.Quantile reads its edges from a linear-interpolation percentile rather than from the weighted one decision 0024 pinned for the medians, because the reference does.

Applies to — net10.0, netstandard2.0.

See also — BrierScore.Score, LogLoss.Score, RocCurve.Compute, the Python equivalence table.