Reduce 3D array by removing NaN elements

Hi !

I ask you for help in Matlab in order to reduce a 3D array. In column there is three numbers (X,Y,Z coordinates) and each row corresponds to a different point. But these points have to respect a certain condition, otherwise three NaN are stored instead of the coordinates. The third dimension correspond to the time evolution of the coordinates stored in the 2D array.

For exemple:

A(:,:,1) =
     1     2     3
   NaN   NaN   NaN
   NaN   NaN   NaN
A(:,:,2) =
   NaN   NaN   NaN
     1     2     3
   NaN   NaN   NaN
A(:,:,3) =
   NaN   NaN   NaN
   NaN   NaN   NaN
   NaN   NaN   NaN

If I try:

A(any(any(isnan(A),3),2),:,:) = [];

I get:

Empty array: 0-by-3-by-3

Or I would have:

A(:,:,1) =
     1     2     3
   NaN   NaN   NaN
A(:,:,2) =
   NaN   NaN   NaN
     1     2     3
A(:,:,3) =
   NaN   NaN   NaN
   NaN   NaN   NaN

The array is reduced but the shape is the same and I don't lose informations.

Thank your for your help and have a nice day !

[the cyclist]

What exactly do you want to get rid of? Any row in which all time slices are NaN?

[Anthony]

No, in fact my 3D array is very huge (50,000 by 3 by 40). I have to display this array on screen, so there is 2,000,000 lines ! It's very huge and it takes a long time to display so many lines. I just want to reduce this 3D array by removing as many "NaN-lines" as I can without erease "coordinates-lines", unlike to the command:

A(any(any(isnan(A),3),2),:,:) = [];

Answer 1

[the cyclist]

Maybe you meant all() instead of any()?

idxToRemove = all(all(isnan(A),3),2);

A(idxToRemove,:,:) = []

Answer 2

[Anthony]

It works perfectly ! Thank you very much ! Could you explain to me how this command works please ? I would understand and not just apply without thinking.