I have a data set of 400 columns and 644rows .I need to select columns 1,2,11,12,​21,22,....​.381,382,3​91,392 or move these particular columns in to a matrix.how can i write code for this in matlab

1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20. from this columns i need to select 1,2,11,12 columns in to one matrix and the remaining in to another matrix. 20 is just an example..i want the answer for 400 columns and 644 rows.

[per isakson]

See

• Indexing, Access array elements
• Matrix Indexing

Answer 1

[Roger Stafford]

If M is the matrix with 400 columns, and if M2 is the matrix to be obtained from it, do this:

   n = 400;
   M2 = M(:,mod((1:n)-1,10)<=1);

[Sindhu Reddy]

thanks how to copy the remaining columns in to another matrix.say from 3 to 10,13 to 20...393 to 400.

[Roger Stafford]

   n = 400;
   M2 = M(:,mod((1:n)-1,10)<=1); % <-- Into one matrix
   M3 = M(:,mod((1:n)-1,10)>=2); % <-- Into the other matrix

Answer 2

[Azzi Abdelmalek]

A=[1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20]
idx=[1,2,11,12]
out1=A(idx)
out2=A(setdiff(1:numel(A),idx))

[Sindhu Reddy]

i have400 columns.i just gave example of 20.i can't list 400 numbers in A matrix

[Azzi Abdelmalek]

Who said to list to list the 400 elements?

Answer 3

[MHN]

A = 1:20;
M1 = A([1,2,11,12]);
M2 = setdiff(A,M1);