dlamch.f man page

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 172 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.

Referenced By

dlamc3(3) and dlamch(3) are aliases of dlamch.f(3).

Sat Nov 16 2013 Version 3.4.2 LAPACK