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- DDDDLLLLAAAAMMMMCCCCHHHH((((3333FFFF)))) DDDDLLLLAAAAMMMMCCCCHHHH((((3333FFFF))))
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- NNNNAAAAMMMMEEEE
- DLAMCH - determine double precision machine parameters
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- SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS
- DOUBLE PRECISION FUNCTION DLAMCH( CMACH )
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- CHARACTER CMACH
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- PPPPUUUURRRRPPPPOOOOSSSSEEEE
- DLAMCH determines double precision machine parameters.
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- AAAARRRRGGGGUUUUMMMMEEEENNNNTTTTSSSS
- 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
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- where
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- 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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- PPPPaaaaggggeeee 1111
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