?gthr

Gathers a full-storage sparse vector's elements into compressed form.

Syntax

call sgthr(nz, y, x, indx )

call dgthr(nz, y, x, indx )

call cgthr(nz, y, x, indx )

call zgthr(nz, y, x, indx )

res = gthr(x, indx, y)

Include Files

  • mkl.fi, blas.f90

Description

The ?gthr routines gather the specified elements of a full-storage sparse vector y into compressed form(nz, x, indx). The routines reference only the elements of y whose indices are listed in the array indx:

x(i) = y(indx(i)), for i=1,2,... ,nz.

Input Parameters

nz

INTEGER. The number of elements of y to be gathered.

indx

INTEGER. Specifies indices of elements to be gathered.

Array, size at least nz.

y

REAL for sgthr

DOUBLE PRECISION for dgthr

COMPLEX for cgthr

DOUBLE COMPLEX for zgthr

Array, size at least max(indx(i)).

Output Parameters

x

REAL for sgthr

DOUBLE PRECISION for dgthr

COMPLEX for cgthr

DOUBLE COMPLEX for zgthr

Array, size at least nz.

Contains the vector converted to the compressed form.

BLAS 95 Interface Notes

Routines in Fortran 95 interface have fewer arguments in the calling sequence than their FORTRAN 77 counterparts. For general conventions applied to skip redundant or reconstructible arguments, see BLAS 95 Interface Conventions.

Specific details for the routine gthr interface are the following:

x

Holds the vector with the number of elements nz.

indx

Holds the vector with the number of elements nz.

y

Holds the vector with the number of elements nz.

For more complete information about compiler optimizations, see our Optimization Notice.