Classification margins by resubstitution
M = resubMargin(obj)
Discriminant analysis classifier, produced using
Numeric column-vector of length
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.
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.
Find the margins for a discriminant analysis classifier for Fisher's iris data by resubstitution. Examine several entries.
Load Fisher's iris data set.
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)
ans = 1.0000 1.0000 0.9998 0.9998 1.0000 0.9946