How to calculate recall and Precision

Hi,

I've a data set of 101 records with 21 classes. First of all I want to generate separately 21 confusion matrix for those 21 classes and then want to calculate recall and precision for this data. Please guide me that how can I write a do it in Matlab.

Thank you.

[Wided HAMMEDI]

%%% matrice de confusion

[confMat,order] = confusionmat(LABEL,target_test);

%%% calcul de la précision , le rappel (recall) et le F-score

%%% recall

for i =1:size(confMat,1)

    recall(i)=confMat(i,i)/sum(confMat(i,:));

end

recall(isnan(recall))=[];

*

Recall*=sum(recall)/size(confMat,1);

%%% précision

for i =1:size(confMat,1)

    precision(i)=confMat(i,i)/sum(confMat(:,i));

end

Precision=sum(precision)/size(confMat,1);

%%% F-score

F_score=2*Recall*Precision/(Precision+Recall); %%F_score=2*1/((1/Precision)+(1/Recall));

[Panashe Chisasa]

thank you so much for this. It helped me with my final year project.

[BANDARU UMAMADHURI]

what does label mean here ??

[OYENIRAN OLUWASHINA]

Thank you so much for the snippet, it really aid my work. Is there any way to calculate recall and precision for each class?