.TH "lamch" 3 "Wed Feb 7 2024 11:30:40" "Version 3.12.0" "LAPACK" \" -*- nroff -*- .ad l .nh .SH NAME lamch \- lamch: machine parameters .SH SYNOPSIS .br .PP .SS "Functions" .in +1c .ti -1c .RI "double precision function \fBdlamch\fP (cmach)" .br .RI "\fBDLAMCH\fP " .ti -1c .RI "real function \fBslamch\fP (cmach)" .br .RI "\fBSLAMCH\fP " .in -1c .SH "Detailed Description" .PP .SH "Function Documentation" .PP .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 .SS "real function slamch (character cmach)" .PP \fBSLAMCH\fP .PP \fBPurpose:\fP .RS 4 .PP .nf SLAMCH determines single 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 SLAMCH: = 'E' or 'e', SLAMCH := eps = 'S' or 's , SLAMCH := sfmin = 'B' or 'b', SLAMCH := base = 'P' or 'p', SLAMCH := eps*base = 'N' or 'n', SLAMCH := t = 'R' or 'r', SLAMCH := rnd = 'M' or 'm', SLAMCH := emin = 'U' or 'u', SLAMCH := rmin = 'L' or 'l', SLAMCH := emax = 'O' or 'o', SLAMCH := 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 .SH "Author" .PP Generated automatically by Doxygen for LAPACK from the source code\&.