ifirstNot

swordfish.function.ifirstNot()

If X is a vector, return the subscript of the first non-null element. Return -1 if all elements are null.

If X is a tuple of vectors, return the subscript of the first position where the element in all vectors is not null.

If X is a matrix, return the subscript of the first non-null element within each column. The result is a vector.

Parameters:

X (Constant) – A vector, or a tuple of vectors of equal length, or a matrix.