vec_dzero_i() — Apollo

VEC_$DZERO_I                      Domain/OS                       VEC_$DZERO_I


NAME
     vec_$dzero_i - zero a vector in a double-precision matrix

SYNOPSIS (C)
     #include <apollo/base.h>
     #include <apollo/vec.h>

     void vec_$dzero_i(
          double *vector,
          long int &inc,
          long int &length)

SYNOPSIS (Pascal)
     %include '/sys/ins/base.ins.pas';
     %include '/sys/ins/vec.ins.pas';

     procedure vec_$dzero_i(
          var vector: univ vec_$double_vector;
          in inc: integer32;
          in length: integer32)

SYNOPSIS (FORTRAN)
     %include '/sys/ins/base.ins.ftn'
     %include '/sys/ins/vec.ins.ftn'

           parameter (nvec = 10)

           double precision vector(nvec)
           integer*4 length, inc

           call vec_$dzero_i(vector, inc, length)

DESCRIPTION
     Vec_$dzero_i zeros the length elements of the double-precision array vec-
     tor selected by inc.

     Through appropriate choice of inc, a program can use vec_$dzero_i to zero
     a vector within a matrix.  To search the Mth vector in a matrix, choose
     inc equal to the number of vectors in the matrix, and place the Mth ele-
     ment of the matrix array at the beginning of vector.

     In C, the resulting operation is

          j = 0;
          for (i = 0; i < length; ++i) {
               vector[i] = 0.0;
               j += inc;
          }

     In Pascal, the resulting operation is

          j := 1;
          for i := 1 to length do
               begin
               vector[i] := 0.0;
               j := j + inc;
               end

     In FORTRAN, the resulting operation is

           j = 1
           do 10 i = 1, length
               vec(j) = 0.0
               j = j + inc
       10  continue

     vector
          The vector to be zeroed.

     inc  An increment for the index of vector that chooses the elements to be
          zeroed.

     length
          The number of elements in vector to zero.

NOTES
     In C and Pascal, vec_$dzero_i zeros a column vector; whereas in FORTRAN,
     it zeros a row vector.

SEE ALSO
     vec_$dzero, vec_$izero16_i, vec_$izero_i, vec_$zero_i.
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