The ISEMPTY function is part of the IMLMLIB library. An empty matrix has no rows or columns. The ISEMPTY function returns 1 if its argument is an empty matrix; otherwise, the function returns 0 as shown in the following example:

free x;   /* an empty matrix */
isX = IsEmpty(x);
y = 1:5;
isY = IsEmpty(y);
print isX isY;