MATLAB: Matrix Question for 12*12 matrix

Question

I have a 12*12 matrix and i want to convert it into 9*9 matrix by eleminating first two colum and first two row and also the forth colum and row, which will leave me a 9*9 matrix. i want to remove 1,2 and 4 column and row from 12*12 matrix?

Answer 1

Supposing M is the 12x12 matrix, then

M([1,2,4],:)=[];
M(:,[1,2,4])=[];

should remove the appropriate rows and columns.