CODEWITHSUNDEEP
matlabsparse-matrix
hhh
hhh

Reputation: 52850

Matlab: command to check for zero sparse matrix?

I need a command to check for zero sparse matrix, isempty(..) does not work. Is there some sparse version of isempty(..)?

>> mlf2=sparse([],[],[],2^31+1,1)

mlf2 =

   All zero sparse: 2147483649-by-1

>> isempty(mlf2)

ans =

     0       % I waited for 1 here with the zero sparse matrix...

Upvotes: 1

Views: 1178

Answers (1)

Samuel O'Malley
Samuel O'Malley

Reputation: 3551

Try

~nnz(mlf2)

or

isempty(find(mlf2))

Edit:

Mohsen Nosratinia pointed out that isempty(find(mlf2), 1) is more efficient because it the find command will either return a matrix of length 1, or an empty matrix

Upvotes: 6

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