dlamch-f(3)

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.