vec_dsub_mult() — Apollo Domain/OS SR10.3.5

VEC_$DSUB_MULT                    Domain/OS                     VEC_$DSUB_MULT


NAME
     vec_$dsub_mult - subtract one single-precision vector from a scalar, mul-
     tiply result by a vector

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

     void vec_$dsub_mult(
          double *mult_vec,
          double *sub_vec,
          long int &length,
          double &constant,
          double *result_vec)

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

     procedure vec_$dsub_mult(
          in mult_vec: univ vec_$double_vector;
          in sub_vec: univ vec_$double_vector;
          in length: integer32;
          in constant: double;
          out result_vec: univ vec_$double_vector);

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

           parameter (nvec = 10)

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

           call vec_$dsub_mult(mult_vec, sub_vec, length, constant, result_vec)

DESCRIPTION
     Vec_$dsub_mult subtracts the vector sub_vec from a scalar constant, mul-
     tiplies the result by the vector mult_vec and stores the final result in
     result_vec.  It differs from vec_$sub_mult in that the vectors being han-
     dled are double-precision floating point.  The calculation performed is
     as follows:

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

     Note that the multiplication done by this call is point-wise.  This call
     does not perform matrix multiplication, since the product of two vectors
     is another vector of the same magnitude.

     mult_vec
          The vector to be multiplied.

     sub_vec
          The vector to be subtracted from constant.

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

     constant
          The scalar constant from which sub_vec is subtracted.

     result_vec
          The vector created by subtracting sub_vec from constant and multi-
          plying mult_vec by  the result.

NOTES
     When vec_$dsub_mult is used to operate on matrixes in C and Pascal,
     mult_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_$sub_mult, vec_$add_mult, vec_$mult_add, vec_$mult_sub,
     vec_$sub_mult_i, vec_$dsub_mult_i, vec_$isub_mult, vec_$isub_mult_i,
     vec_$isub_mult16, vec_$isub_mult16_i.
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