resubMargin

Class: ClassificationDiscriminant

Classification margins by resubstitution

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Syntax

M = resubMargin(obj)

Description

M = resubMargin(obj) returns resubstitution classification margins for obj.

Input Arguments

obj

Discriminant analysis classifier, produced using fitcdiscr.

Output Arguments

`M`	Numeric column-vector of length `size(obj.X,1)` containing the classification margins.

Examples

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Estimate Resubstitution Margins for Discriminant Analysis Classifiers

Open Live Script

Find the margins for a discriminant analysis classifier for Fisher's iris data by resubstitution. Examine several entries.

Load Fisher's iris data set.

load fisheriris

Train a discriminant analysis classifier.

Mdl = fitcdiscr(meas,species);

Compute the resubstitution margins, and display several of them.

m = resubMargin(Mdl);
m(1:25:end)

More About

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Margin

The classification margin is the difference between the classification score for the true class and maximal classification score for the false classes.

The classification margin is a column vector with the same number of rows as in the matrix X. A high value of margin indicates a more reliable prediction than a low value.

Score

For discriminant analysis, the score of a classification is the posterior probability of the classification. For the definition of posterior probability in discriminant analysis, see Posterior Probability.

Documentation