.TH "dlamch.f" 3 "Wed Oct 15 2014" "Version 3.4.2" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME dlamch.f \- .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "double precision function \fBdlamch\fP (CMACH)" .br .RI "\fI\fBDLAMCH\fP \fP" .ti -1c .RI "double precision function \fBdlamc3\fP (A, B)" .br .RI "\fI\fBDLAMC3\fP \fP" .in -1c .SH "Function/Subroutine Documentation" .PP .SS "double precision function dlamc3 (double precisionA, double precisionB)" .PP \fBDLAMC3\fP \fBPurpose:\fP .PP .nf 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. .fi .PP .PP \fBAuthor:\fP .RS 4 LAPACK is a software package provided by Univ\&. of Tennessee, Univ\&. of California Berkeley, Univ\&. of Colorado Denver and NAG Ltd\&.\&. .RE .PP \fBDate:\fP .RS 4 November 2011 .RE .PP \fBParameters:\fP .RS 4 \fIA\fP .PP .nf A is a DOUBLE PRECISION .fi .PP .br \fIB\fP .PP .nf B is a DOUBLE PRECISION The values A and B. .fi .PP .RE .PP .PP Definition at line 172 of file dlamch\&.f\&. .SS "double precision function dlamch (characterCMACH)" .PP \fBDLAMCH\fP .PP \fBPurpose: \fP .RS 4 .PP .nf DLAMCH determines double precision machine parameters. .fi .PP .RE .PP \fBParameters:\fP .RS 4 \fICMACH\fP .PP .nf 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) .fi .PP .RE .PP \fBAuthor:\fP .RS 4 Univ\&. of Tennessee .PP Univ\&. of California Berkeley .PP Univ\&. of Colorado Denver .PP NAG Ltd\&. .RE .PP \fBDate:\fP .RS 4 November 2011 .RE .PP .PP Definition at line 64 of file dlamch\&.f\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.