problems with training function LVQ

Hi all, I need your help

image1=imread('img1.bmp');

image2=imread('img2.bmp');

image3=imread('img3.bmp');

P = [image1 image2 image3 ]

T = [[1;0;0] [0;1;0] [0;0;1] ]

net = newlvq(minmax(P),9,[.34 .33 .33]);

net.trainParam.epochs = 1000;

net.trainParam.goal=0.00001;

net = train(net,P,T)

when I run this code, I take this error : Error using -> minmax

please help me !

Thanks..