Shrinking a Sparse Matrix

I have a sparse matrix and I want to kind of shrink its size by storing just one column per every 10 columns in the matrix. Is there a way to do this?

[Steven Lord]

Please give a small example of how you want to collapse 10 columns down into 1. Do you want to add the columns together, take the average, take just the first of each group of ten, or something more complicated?

[Manjot Singh]

I just wanted to take the first out of each 10 columns, as Walter Roberson has mentioned below. But now you have mentioned that, can you tell me how we can take average of these columns?

Answer 1

[Walter Roberson]

NewMatrix = YourMatrix(:,1:10:end);

[Manjot Singh]

This was what I was looking for. Thank you.

[Walter Roberson]

To take the mean:

(YourMatrix(:,1:10:end) + YourMatrix(:,2:10:end) + YourMatrix(:,3:10:end) .... YourMatrix(:,10:10:end))/10

You might want to use a loop:

NewMatrix = YourMatrix(:,1:10:end);
for K = 2 : 10
  NewMatrix = NewMatrix(:,K:10:end);
end
NewMatrix = NewMatrix / 10;