slasq6(3S)

SLASQ6 - compute one dqd (shift equal to zero) transform in ping-pong form, with protection against underflow and overflow

Showing IRIX 6.5.30 (default release). Added in IRIX 6.5.15.

NAME
     SLASQ6 - compute one dqd (shift equal to zero) transform in ping-pong
     form, with protection against underflow and overflow

SYNOPSIS
     SUBROUTINE SLASQ6( I0, N0, Z, PP, DMIN, DMIN1, DMIN2, DN, DNM1, DNM2 )

         INTEGER        I0, N0, PP

         REAL           DMIN, DMIN1, DMIN2, DN, DNM1, DNM2

         REAL           Z( * )

IMPLEMENTATION
     These routines are part of the SCSL Scientific Library and can be loaded
     using either the -lscs or the -lscs_mp option.  The -lscs_mp option
     directs the linker to use the multi-processor version of the library.

     When linking to SCSL with -lscs or -lscs_mp, the default integer size is
     4 bytes (32 bits). Another version of SCSL is available in which integers
     are 8 bytes (64 bits).  This version allows the user access to larger
     memory sizes and helps when porting legacy Cray codes.  It can be loaded
     by using the -lscs_i8 option or the -lscs_i8_mp option. A program may use
     only one of the two versions; 4-byte integer and 8-byte integer library
     calls cannot be mixed.

PURPOSE
     SLASQ6 computes one dqd (shift equal to zero) transform in ping-pong
     form, with protection against underflow and overflow.

ARGUMENTS
     I0    (input) INTEGER
           First index.

     N0    (input) INTEGER
           Last index.

     Z     (input) REAL array, dimension ( 4*N )
           Z holds the qd array. EMIN is stored in Z(4*N0) to avoid an extra
           argument.

     PP    (input) INTEGER
           PP=0 for ping, PP=1 for pong.

     DMIN  (output) REAL
           Minimum value of d.

           DMIN1 (output) REAL Minimum value of d, excluding D( N0 ).

           DMIN2 (output) REAL Minimum value of d, excluding D( N0 ) and D(
           N0-1 ).
     DN    (output) REAL
           d(N0), the last value of d.

     DNM1  (output) REAL
           d(N0-1).

     DNM2  (output) REAL
           d(N0-2).

SEE ALSO
     INTRO_LAPACK(3S), INTRO_SCSL(3S)

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