.TH "INSTALL/dlamch.f" 3 "Version 3.12.0" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME INSTALL/dlamch.f .SH SYNOPSIS .br .PP .SS "Functions/Subroutines" .in +1c .ti -1c .RI "double precision function \fBdlamch\fP (cmach)" .br .RI "\fBDLAMCH\fP " .ti -1c .RI "double precision function \fBdlamc3\fP (a, b)" .br .RI "\fBDLAMC3\fP " .in -1c .SH "Function/Subroutine Documentation" .PP .SS "double precision function dlamc3 (double precision a, double precision b)" .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 \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 \fB171\fP of file \fBdlamch\&.f\fP\&. .SS "double precision function dlamch (character cmach)" .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 !> CMACH is CHARACTER*1 !> 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 .PP Definition at line \fB68\fP of file \fBdlamch\&.f\fP\&. .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.