pdlamch(3) [debian man page]

PDLAMCH(l)					      LAPACK auxiliary routine (version 1.5)						PDLAMCH(l)

NAME

       PDLAMCH - determine double precision machine parameters

SYNOPSIS

       DOUBLE PRECISION FUNCTION PDLAMCH( ICTXT, CMACH )

	   CHARACTER	CMACH

	   INTEGER	ICTXT

PURPOSE

       PDLAMCH determines double precision machine parameters.

ARGUMENTS

       ICTXT   (global input) INTEGER
	       The BLACS context handle in which the computation takes place.

       CMACH   (global input) CHARACTER*1
	       Specifies the value to be returned by PDLAMCH:
	       = 'E' or 'e',   PDLAMCH := eps
	       = 'S' or 's ,   PDLAMCH := sfmin
	       = 'B' or 'b',   PDLAMCH := base
	       = 'P' or 'p',   PDLAMCH := eps*base
	       = 'N' or 'n',   PDLAMCH := t
	       = 'R' or 'r',   PDLAMCH := rnd
	       = 'M' or 'm',   PDLAMCH := emin
	       = 'U' or 'u',   PDLAMCH := rmin
	       = 'L' or 'l',   PDLAMCH := emax
	       = 'O' or 'o',   PDLAMCH := rmax

	       where

       eps   = relative machine precision
	     sfmin  = safe minimum, such that 1/sfmin does not overflow base  = base of the machine prec  = eps*base t	   = number of (base) dig-
	     its in the mantissa rnd   = 1.0 when rounding occurs in addition, 0.0 otherwise emin  = minimum exponent before  (gradual)  underflow
	     rmin    =	 underflow  threshold  -  base**(emin-1)  emax	 =  largest  exponent  before  overflow  rmax	=  overflow  threshold	 -
	     (base**emax)*(1-eps)

LAPACK version 1.5						    12 May 1997 							PDLAMCH(l)

dlamch.f(3)							      LAPACK							       dlamch.f(3)

NAME

       dlamch.f -

SYNOPSIS

   Functions/Subroutines
       DOUBLE PRECISION function dlamch (CMACH)
	   DLAMCH
       DOUBLE PRECISION function dlamc3 (A, B)
	   DLAMC3

Function/Subroutine Documentation
   DOUBLE PRECISION function dlamc3 (double precisionA, double precisionB)
       DLAMC3 Purpose:

	DLAMC3	is intended to force  A  and  B  to be stored prior to doing
	the addition of  A  and  B ,  for use in situations where optimizers
	might hold one of these in a register.

       Author:
	   LAPACK is a software package provided by Univ. of Tennessee, Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..

       Date:
	   November 2011

       Parameters:
	   A

		     A is a DOUBLE PRECISION

	   B

		     B is a DOUBLE PRECISION
		     The values A and B.

       Definition at line 168 of file dlamch.f.

   DOUBLE PRECISION function dlamch (characterCMACH)
       DLAMCH Purpose:

	    DLAMCH determines double precision machine parameters.

       Parameters:
	   CMACH

		     Specifies the value to be returned by DLAMCH:
		     = 'E' or 'e',   DLAMCH := eps
		     = 'S' or 's ,   DLAMCH := sfmin
		     = 'B' or 'b',   DLAMCH := base
		     = 'P' or 'p',   DLAMCH := eps*base
		     = 'N' or 'n',   DLAMCH := t
		     = 'R' or 'r',   DLAMCH := rnd
		     = 'M' or 'm',   DLAMCH := emin
		     = 'U' or 'u',   DLAMCH := rmin
		     = 'L' or 'l',   DLAMCH := emax
		     = 'O' or 'o',   DLAMCH := rmax
		     where
		     eps   = relative machine precision
		     sfmin = safe minimum, such that 1/sfmin does not overflow
		     base  = base of the machine
		     prec  = eps*base
		     t	   = number of (base) digits in the mantissa
		     rnd   = 1.0 when rounding occurs in addition, 0.0 otherwise
		     emin  = minimum exponent before (gradual) underflow
		     rmin  = underflow threshold - base**(emin-1)
		     emax  = largest exponent before overflow
		     rmax  = overflow threshold  - (base**emax)*(1-eps)

       Author:
	   Univ. of Tennessee

	   Univ. of California Berkeley

	   Univ. of Colorado Denver

	   NAG Ltd.

       Date:
	   November 2011

       Definition at line 64 of file dlamch.f.

Author
       Generated automatically by Doxygen for LAPACK from the source code.

Version 3.4.2							  Tue Sep 25 2012						       dlamch.f(3)