vec_dsub_vector()

VEC_$DSUB_VECTOR                  Domain/OS                   VEC_$DSUB_VECTOR


NAME
     vec_$dsub_vector - subtract two double-precision vectors

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

     void vec_$dsub_vector(
          double *start_vec,
          double *sub_vec,
          long int &length,
          double *result_vec)

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

     procedure vec_$dsub_vector(
          in start_vec: univ vec_$double_vector;
          in sub_vec: univ vec_$double_vector;
          in length: integer32;
          out result_vec: univ vec_$double_vector);

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

           parameter (nvec = 10)

           real*8 start_vec(nvec), result_vec(nvec), sub_vec(nvec)
           integer*4 length

           call vec_$dsub_vector(start_vec, sub_vec, length, result_vec)

DESCRIPTION
     Vec_$dsub_vector subtracts the vector sub_vec from start_vec and stores
     the final result in result_vec.  It differs from vec_$sub_vector in that
     the argument vectors are double-precision floating-point.  The calcula-
     tion performed is as follows:

     For each integer I such that 1 <= I <= length,
     result_vec(I) = start_vec(I) - sub_vec(I)

     start_vec
          A vector to be subtracted from.

     sub_vec
          A vector to be subtracted.

     length
          The number of elements to be operated on;  normally the same as the
          number of elements in the vectors.

     result_vec
          The vector created by subtracting sub_vec from start_vec.

NOTES
     When vec_$dsub_vector is used to operate on matrixes in C and Pascal,
     start_vec, sub_vec, and result_vec are row vectors; in FORTRAN, they are
     column vectors.

     As in all the vec_$ calls, the result array must not overlap any of the
     input arrays; the result array may be identical to an input, but must not
     contain any subset of it.   Because of pipelining, using overlapping
     input and output arrays may cause incorrect results.


SEE ALSO
     vec_$add_vector, vec_$mult_vector, vec_$sub_vector_i, vec_$sub_vector,
     vec_$dsub_vector_i, vec_$isub_vector, vec_$isub_vector_i,
     vec_$isub_vector16, vec_$isub_vector16_i.
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