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Diffstat (limited to 'Doc/Elementary Functions/dlamch.help')
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diff --git a/Doc/Elementary Functions/dlamch.help b/Doc/Elementary Functions/dlamch.help new file mode 100644 index 00000000..b65cae07 --- /dev/null +++ b/Doc/Elementary Functions/dlamch.help @@ -0,0 +1,39 @@ +/* -- LAPACK auxiliary routine (version 3.0) -- + Univ. of Tennessee, Univ. of California Berkeley, NAG Ltd., + Courant Institute, Argonne National Lab, and Rice University + October 31, 1992 + + + Purpose + ======= + + DLAMCH determines double precision machine parameters. + + Arguments + ========= + + CMACH (input) 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)
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