cgthr

NAME

cgthr, dgthr, sgthr, zgthr - Gathers specified elements from y into x

SYNOPSIS

  SUBROUTINE CGTHR( NZ, Y, X, INDX)
  COMPLEX Y(*), X(*)
  INTEGER NZ
  INTEGER INDX(*)
 
  SUBROUTINE CGTHR_64( NZ, Y, X, INDX)
  COMPLEX Y(*), X(*)
  INTEGER*8 NZ
  INTEGER*8 INDX(*)

F95 INTERFACE

  SUBROUTINE GTHR( [NZ], Y, X, INDX)
  COMPLEX, DIMENSION(:) :: Y, X
  INTEGER :: NZ
  INTEGER, DIMENSION(:) :: INDX
 
  SUBROUTINE GTHR_64( [NZ], Y, X, INDX)
  COMPLEX, DIMENSION(:) :: Y, X
  INTEGER(8) :: NZ
  INTEGER(8), DIMENSION(:) :: INDX

PURPOSE

cgthr xGTHR - Gathers the specified elements from a vector y in full storage form into a vector x in compressed form. Only the elements of y whose indices are listed in indx are referenced.

             do 10, i = 1, n
               x(i) = y(indx(i))
          10 continue

ARGUMENTS

* NZ (input)

- INTEGER

Number of elements in the compressed form. Unchanged on exit.

* Y (input)

Vector in full storage form. Unchanged on exit.

* X (output)

Vector in compressed form. Contains elements of y whose indices are listed in indx on exit.

* INDX (input)

- INTEGER

Vector containing the indices of the compressed form. It is assumed that the elements in INDX are distinct and greater than zero. Unchanged on exit.