Asked by Emerson De Souza
on 18 Nov 2012

Hi, I have a table XYZ with three columns (xyz) as below:

1 1 1 1 2 2 1 3 3 2 1 4 2 2 5 2 3 6 3 1 7 3 2 8 3 3 9

and I want to transform it into a Mxy-Matrix with Z as value for each Mxy pair as follows:

1 4 7 2 5 8 3 6 9

On the other hand I may have directly the Matrix Mxy and would like to obtain the XYZ-table.

I already tried mesh, meshgrid, ndgrid, surf and etc... as documented, but nothing worked as I wished. It is possible that I did not understand yet how to use this commands.

I wonder if someone could tell me how to write the command to convert:

1) Table XYZ to Matrix Mxy with Z as values of each Mxy-pair 2) Matrix Mxy to Table XYZ

I thank you in advance for your help

Emerson

Answer by Walter Roberson
on 18 Nov 2012

Accepted answer

accumarray(XYZ(:,[2 1]), XYZ(:,3)]

Emerson De Souza
on 18 Nov 2012

Thank you Walter, your suggestion works fine as below

xvector = 1:1:3; yvector = 1:1:3; numX = numel(xvector); numY = numel(yvector); yvector = repmat(yvector(:),numX,1); xvector = repmat(xvector ,numY,1); XY = [xvector(:) yvector]; Z=(1:1:length(XY))';

XYZ=[XY Z]; M=accumarray(XYZ(:,[2 1]), XYZ(:,3));

Now, if M is given, how do I obtain XYZ?

Thank you in advance

Emerson

Emerson De Souza
on 19 Nov 2012

Thank you Walter, your suggestions fixed my problem. Wish you a nice day

Emerson

Opportunities for recent engineering grads.

## 0 Comments