CERROR | ![]() |
Computes classification error.
Synopsis:
error = cerror(y1,y2)
error = cerror(y1,y2,label)
Description:
error = cerror(y1,y2) returns classification error, i.e.,
error= 1/length(y1) sum_i L( y1(i), y2(i))
where L(a,b)=0 if a==b and L(a,b)=1 if a ~= b.
error = cerror(y1,y2,label) considers only labels
find(y2==label), i.e., if y1,y2 from {-1,1} then
false_positives_rate = cerror(y1,y2,-1)
false_negatives_rate = cerror(y1,y2,+1)
Input:
y1 [1 x n] Vector of integers (response of classifier).
y2 [1 x n] Vector of integers (ground truth).
label [int] Selected label.
Output:
error [real] Error.
Example:
classifier = [+1,+1,+1,-1]
groundtruth = [-1,+1,-1,+1]
error = cerror(classifier,groundtruth)
false_pos = cerror(classifier,groundtruth,-1)
false_neg = cerror(classifier,groundtruth,1)
See also
ROC
About: Statistical Pattern Recognition Toolbox
(C) 1999-2003, Written by Vojtech Franc and Vaclav Hlavac
Czech Technical University Prague
Faculty of Electrical Engineering
Center for Machine Perception
Modifications:
09-jun-2004, VF
14-Jan-2003, VF