Language Reference

COUNT(MASK, DIM)

Counts the number of true array elements in an entire logical array, or in each vector along a single dimension. Typically, the logical array is one that is used as a mask in another intrinsic.

MASK

is a logical array.

DIM (optional)

is an integer scalar in the range 1 <= DIM <= rank(MASK). The corresponding actual argument must not be an optional dummy argument.

Class

Transformational function

Result Value

If DIM is present, the result is an integer array of rank rank(MASK)-1. If DIM is missing, or if MASK has a rank of one, the result is a scalar of type integer.

Each element of the resulting array (R(s₁, s₂, ..., s_(DIM-1), s_(DIM+1), ..., s_n)) equals the number of elements that are true in MASK along the corresponding dimension (s₁, s₂, ..., s_(DIM-1), :, s_(DIM+1), ..., s_n).

If MASK is a zero-sized array, the result equals zero.

Examples

! A is the array | T F F |, and B is the array | F F T |
!                | F T T |                     | T T T |
 
! How many corresponding elements in A and B
! are equivalent?
    RES = COUNT(A .EQV. B)        ! result RES is 3
 
! How many corresponding elements are equivalent
! in each column?
    RES = COUNT(A .EQV. B, DIM=1) ! result RES is (0,2,1)
 
! Same question, but for each row.
    RES = COUNT(A .EQV. B, DIM=2) ! result RES is (1,2)