Hi,
There seems to be a mismatch between number of Observation Labels (chemical names) and number of rows in ‘score’ matrix. Number of Observation Labels must be same as number of rows in ‘score’ matrix. In question it is mentioned that number of variables is 14, but ‘Pah’ has 15 labels. To avoid the mismatch please check the size of ‘score’ matrix and provide equal number of labels in ‘Pah’ variable.
Also, I created a sample ‘spw’ variable of size 15x9 with random numbers and tested in the code as provided by you. It seems to work fine.
spw = randn(15,9);%Random numbers
Z = zscore(spw); % Standardized data
[coefs,score,v,g,ex] = pca(Z);
vbls = {'1','2','3','4','5','6','7','8', '9'}; % Array of variable labels for houses
Pah={'Naph','2Methyl','1Methyl','Acy','Ace','Flu','Phe','Ant','Flt','Pyr','BaAnt', 'Chr', 'BbFlu','BkFLu','BePyr'};% chem names
h6 = biplot(coefs(:,1:2),'Scores',score(:,1:2),'ObsLabels',Pah, 'VarLabels', vbls);
Hope this helps!
