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DOUBLE PRECISION FUNCTION D1MACH(I)
C
C Double-precision machine constants.
C This implementation for use in MATLAB Fortran Mex-files.
C
C D1MACH(1) = realmin = B**(EMIN-1), the smallest positive magnitude.
C D1MACH(2) = realmax = B**EMAX*(1 - B**(-T)), the largest magnitude.
C D1MACH(3) = eps/2 = B**(-T), the smallest relative spacing.
C D1MACH(4) = eps = B**(1-T), the largest relative spacing.
C D1MACH(5) = LOG10(B)
C
c 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)
*
double precision DLAMCH
IF (I .EQ. 1) D1MACH = DLAMCH('U')
IF (I .EQ. 2) D1MACH = DLAMCH('O')
IF (I .EQ. 3) D1MACH = DLAMCH('E')
IF (I .EQ. 4) D1MACH = DLAMCH('P')
IF (I .EQ. 5) D1MACH = log10(DLAMCH('B'))
RETURN
END
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