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VEC_$DNEG                         Domain/OS                          VEC_$DNEG


NAME
     vec_$dneg - take the negative of a double-precision vector

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

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

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

     procedure vec_$dneg(
          in start_vec: univ vec_$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)
           integer*4 length

           call vec_$dneg(start_vec, length, result_vec)

DESCRIPTION
     Vec_$dneg places the negative of the vector start_vec into result_vec.
     (The negative of a vector contains the negatives of all the original
     vector's elements.)  The calculation performed is as follows:

     For each integer I such that 1 <= I <= count,
     result_vec(I) = -1 x start_vec(I)

     start_vec
          The vector whose negative is required.

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

     result_vec
          The negative of the vector start_vec.

NOTES
     When vec_$dneg is used to operate on matrixes in C and Pascal, start_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_$abs, vec_$neg_i, vec_$neg, vec_$dneg_i, vec_$ineg, vec_$ineg_i,
     vec_$ineg16, vec_$ineg16_i.