partitioning a matrix based on another

I have two matrices,say, X=[1 2 2; 2 3 3; 3 5 5 ;6 1 2; 3 4 3] and ng=[2;3]. I want to partition X based on ng, i.e.

x1=[1 2 2; 2 3 3], i.e. taking the ng(1) number of rows x2=[3 5 5 ;6 1 2; 3 4 3] , ng(2) number of rows where

X=[x1;x2].

I can do it using a for loop, but is there any efficient way to do this? This is just an example, there can be a larger ng, and also x

[Thomas]

do you always have two elements in ng? or can you have more?

[Jan]

I assume, the FOR loop will be the most efficient method - it is required inside MAT2CELL also. If you post your code, we could potentially find improvements.

Answer 1

[Andrei Bobrov]

k = mat2cell(X,ng,size(X,2))
[x1,x2] = k{:}

Answer 2

[Honglei Chen]

If your matrix can be exactly partitioned, you can use mat2cell. In your problem, X has 5 lines, which cannot be evenly divided by your ng, so I added one line

X=[1 2 2; 2 3 3; 3 5 5 ;6 1 2; 3 4 3; 5 3 2]
y =  mat2cell(X,ng(1)*ones(1,size(X,1)/ng(1)),ng(2)*ones(1,size(X,2)/ng(2)))

[Rabeya]

I want to partition it, depending on ng

[Honglei Chen]

Did you try? Each cell of y holds a partition.