How to zoom out / shrink the matrix to the desired matrix

Hi guys, I have a question. I have an 8 by 8 matrix for instance, and I tried to shrink it into 5 by 5 matrix. Does the Matlab have the way to do that? I try to extract the odd element in rows and columns but it cannot the exact size of the matrix I want. For example Y = I(1:2: end,1:2: end) and in 8 by 8 matrix case, it will only output the 4 by 4 matrix. Thank you

Answer 1

[Stephen23]

You can use interp2, e.g.:

M = your 8x8 matrix
V = linspace(1,8,5);
interp2(M,V,V.')

See also:

https://www.mathworks.com/help/matlab/interpolation.html

https://www.mathworks.com/help/matlab/math/interpolating-gridded-data.html

[Yiqing Zhou]

Thank you, Stephen. Let me try it

[Yiqing Zhou]

Hi Stephen. I have tried the code you provided and it gave me the 1 by 5 matrix. Would do mind if you recheck it? Thank you.

[Walter Roberson]

interp2(M, V, V.')

[Yiqing Zhou]

It works, thank you, Roberson.