VEC_$ABS                          Domain/OS                           VEC_$ABS


NAME
     vec_$abs - take the absolute value of the elements in a single-precision
     vector

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

     void vec_$abs(
          float *start_vec,
          long int &length,
          float *result_vec)

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

     procedure vec_$abs(
          in start_vec: univ vec_$real_vector;
          in length: integer32;
          out result_vec: univ vec_$real_vector);

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

           parameter (nvec = 10)

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

           call vec_$abs(start_vec, length, result_vec)

DESCRIPTION
     Vec_$abs places the absolute value of the entries in the vector start_vec
     into result_vec.  The calculation performed is as follows:

     For each integer I such that 1 <= I <= length,

     result_vec(I) = |start_vec(I)|
                     |            |
     start_vec
          The vector whose absolute value is required.

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

     result_vec
          The absolute value of the vector start_vec.

NOTES
     When vec_$abs 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_$neg, vec_$abs_i, vec_$dabs, vec_$dabs_i, vec_$iabs, vec_$iabs_i,
     vec_$iabs16, vec_$iabs16_i.