How to do Multi SVM classifcation for hyperspecral imagery . my data is Hyperion

i have tried to do this by an approach where i get to reduce the bands by a method called Modified broken stick rule were i get to use the Eigen Value (using covariance)of each band. i tried to load the image but it showed "out of memory" error. so, i tried to load 25 bands first. but still i am not able to find the eigen values using eig function.i don't know how to convert 3D to 2D matrix.! and i am yet to do the classification part .please do help .!i tried to read the image using "multibandread" function and it worked fine.! please do not suggest me Hyperspectral Image Analyst Tool Box.... It doesnt work!!