Function similar to isnan for zeros

Is there a function that does what isnan does but with zeros?

Answer 1

[Matt J]

 The ~ operator

    >> A=[1 0 2 3 0 0 4]

    A =

         1     0     2     3     0     0     4

    >> nonzeroMap=~A

    nonzeroMap =

         0     1     0     0     1     1     0

[Matt J]

Or the not() command

      >> nonzeroMap=not(A)

    nonzeroMap =

         0     1     0     0     1     1     0