vector-count

[procedure] vector-count pred vec1 vec2 ...

SRFI-43: Returns a number of elements in vectors that satisfy pred.

(vector-count (lambda (i elt) (even? elt)) '#(3 1 4 1 5 9 2 5 6))
 => 3

(vector-count (lambda (i x y) (< x y)) '#(1 3 6 9) '#(2 4 6 8 10 12))
 => 2