Remove Inf and NaN values in a Point Cloud in the fastest way

If I have a matrix A

A = [1, 11, 21; NaN,12, 22; 3, 13, Inf; NaN,14, NaN; 5, Inf, NaN; 6, 16, 26];

I want to eliminate all rows which have either Inf or NaN elements.

So the expected result would be : [1, 11, 21; 6, 16, 26];

Since I will be working with images of dimensions 4000 X 3000, I want a very fast and efficient way of doing this.

Thank you =)

Answer 1

[Adam]

A = A( ~any( isnan( A ) | isinf( A ), 2 ),: )

[Meghana Dinesh]

Another similar question; the way

A = A( ~any( isnan( A ) | isinf( A ), 2 ),: )

removes the entire row if NaN or Inf is encountered, I want to remove the entire row if it does not fall within a particular range......i.e., if there's any element x, where 0 < x < 100, eliminate the row.

I tried:

Res= A(~any(A<100)|(A>0),2),:);

But doesn't work.

[Adam]

any( A > 0 & A < 100, 2 )

will give you the indices of all rows satisfying 0 < A < 100. So

A = A( ~any( A > 0 & A < 100, 2 ), : );

will remove those rows from A.

I often prefer to do things like that in the two lines for better readability, so:

idx = any( A > 0 & A < 100, 2 );
A = A( ~idx );

That way you can also easily double-check the intermediate indexing result before it deletes the wrong rows of your matrix!

Your version was lacking a '(' somewhere, but also the ,2 argument is for the 'any' function, telling it to run on the 2nd dimension. To be honest I always get mixed up with rows and columns and dimension 1 and 2 so I just try them out until I get the right one!

[Meghana Dinesh]

Thank you =) I couldn't find all this explanation on tutorials. Learning to use these functions comes from experience :D

Answer 2

[Vignesh Kumar]

%%Try this. It worked for me
A = [1, 11, 21; NaN,12, 22; 3, 13, Inf; NaN,14, NaN; 5, Inf, NaN; 6, 16, 26];
Anew=A((isfinite(A)))

Anew = 12×1

1 3 5 6 11 12 13 14 16 21