VEC_$DSUB_ADD_VECTOR              Domain/OS               VEC_$DSUB_ADD_VECTOR


NAME
     vec_$dsub_add_vector - add two double-precision vectors, subtract a third

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

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

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

     procedure vec_$dsub_add_vector(
          in start_vec: univ vec_$double_vector;
          in sub_vec: univ vec_$double_vector;
          in add_vec: univ vec_$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), add_vec(nvec)
           integer*4 length

           call vec_$dsub_add_vector(start_vec, sub_vec, add_vec, length, result_vec)

DESCRIPTION
     Vec_$dsub_add_vector subtracts the vector sub_vec from start_vec, adds
     add_vec to the result, and stores the final result in result_vec.  It
     differs from vec_$sub_add_vector in that the vectors being handled are
     double-precision floating point.  The calculation performed is as fol-
     lows:

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

     start_vec
          An addend vector.

     sub_vec
          A vector to be subtracted.

     add_vec
          An addend vector.

     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 and adding
          add_vec.

NOTES
     When vec_$dsub_add_vector is used to operate on matrixes in C and Pascal,
     start_vec, sub_vec, add_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_$add_mult_vector, vec_$sub_mult_vector, vec_$mult_add_vector,
     vec_$mult_sub_vector, vec_$mult_rsub_vector, vec_$add_add_vector,
     vec_$mult_mult_vector, vec_$sub_add_vector, vec_$sub_add_vector_i,
     vec_$dsub_add_vector_i, vec_$isub_add_vector, vec_$isub_add_vector_i,
     vec_$isub_add_vector16, vec_$isub_add_vector16_i.