Changing order of matrix and add values

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Hello
I have a matrix ( nDestinations x nRoutes )
A = 1 0 0 1 1 1
0 2 0 2 0 2
0 0 3 0 3 3
I want to; first sort the matrix like this: (Get all positive values at the top)
A = 1 2 3 1 1 1
0 0 0 2 3 2
0 0 0 0 0 3
And last I want to add a value, and a last row with the value nDestinations +1, in this case 4
A = 1 2 3 1 1 1
4 4 4 2 3 2
4 4 4 4 4 3
4 4 4 4 4 4
Is this even possible ?
Thanks!

Accepted Answer

Thorsten
Thorsten on 10 Nov 2015
Edited: Thorsten on 10 Nov 2015
A = [1 0 0 1 1 1
0 2 0 2 0 2
0 0 3 0 3 3];
To sort only the positive values, the zero values are set to NaN:
A(A==0) = nan;
Now sort each column:
for i=1:size(A,2), A(:,i) = sort(A(:,i)); end
Replace the NaN with zeros:
A(isnan(A)) = 0;
Add a new final row of zeros:
A(end+1, end) = 0;
Set all zeros to the maximum element in A + 1:
A(A==0) = max(A(:)) + 1;
  3 Comments
Stephen23
Stephen23 on 10 Nov 2015
Note that sort also supports a dimension argument, which means that the third step "Now sort each column" can be performed without any loop:
>> sort(A,1)
ans =
1 2 3 1 1 1
NaN NaN NaN 2 3 2
NaN NaN NaN NaN NaN 3
Thorsten
Thorsten on 10 Nov 2015
I guessed that there's a smarter way to sort columns. Thank you, Stephen to point that out.

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