Delete rows from matrix

Hallo,I need help!

I have 110 matrix 64 line x 2200 column and I would like to delete some columns from each matrix, so I am obliged to use loops for each matrix. I am looking for a predefined function to delete the columns. This is a small algorithm explaining what I mean:

for i=1:110

delete( matrix(:,j:j+5)) from matrix;

end

[Image Analyst]

WHY are you obligated to use loops rather than the vectorized method the others suggested? Do you just think you do (because you don't know how to use MATLAB's vectorization capability), or did your professor/instructor mandate it?

[Amal]

I have other instruction in the same loop and I need each iteration a matrix, each matrix contains the same columns, but in different order. I think my problem is solved finally :) I am waiting for matlab execution to verify my matrix. I used this instruction: matrix(:,j:j+5)=[];

thank you for your help :)

Answer 1

[Giorgos Papakonstantinou]

IN the title you mention rows. In the question you mention columns. example:

A1=randi(10,64, 2200);
A2=randi(10,64, 2200);
A3=randi(10,64, 2200);
...
An=randi(10,64, 2200);

mat=[A1;A2;A3;...An];

startcolumn=11;
step=11;
mat(:,[startcolumn:step:end])=[]

[Amal]

thank you so much, I used the last instruction from the beginning, but it didn't work, but after restarting MATLAB it worked ;)

Answer 2

[Iain]

To "delete"

 matrix = eye(5);%5x5 identity matrix
 list_o_cols_to_delete = [1 3 5];
 matrix(:,list_o_cols_to_delete) = []

To only use the bits you want:

 matrix = eye(5);%5x5 identity matrix
 list_o_cols_to_use = [1 3 5];
 used = matrix(:,list_o_cols_to_use)