ifirstNot
Syntax
ifirstNot(X)
Arguments
X is a vector, or a tuple of vectors of equal length, or a matrix.
Details
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.
Examples
$ ifirstNot(NULL NULL 2 4 8 NULL 1);
2
$ ifirstNot(take(int(),5));
-1
$ x=NULL NULL 4 7 8 NULL
$ y=1 NULL NULL 4 NULL NULL
$ ifirstNot([x,y]);
3
$ x=NULL NULL 4 7 8 NULL
$ y=1 2 NULL NULL NULL 6
$ ifirstNot([x,y]);
-1
$ m=matrix(0 NULL 1 2 3, NULL 2 NULL 0 3);
$ m;
#0 |
#1 |
|---|---|
0 |
|
2 |
|
1 |
|
2 |
0 |
3 |
3 |
$ ifirstNot(m);
[0,1]