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# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc.
include <mach.h>
# FP_NORMD -- Normalize a double precision number x to the value NORMX, in the
# range [1-10). EXPON is returned such that x = normx * (10.0d0 ** expon).
procedure fp_normd (x, normx, expon)
double x # number to be normalized
double normx # X normalized to the range 1-10 (output)
int expon # exponent of normalized X
double absx, tol
begin
tol = EPSILOND * 10.0D0
absx = abs (x)
expon = 0
if (absx > 0) {
while (absx < (1.0D0 - tol)) {
absx = absx * 10.0D0
expon = expon - 1
if (absx == 0.0D0) { # check for underflow to zero
normx = 0
expon = 0
return
}
}
while (absx >= (10.0D0 + tol)) {
absx = absx / 10.0D0
expon = expon + 1
}
}
if (x < 0)
normx = -absx
else
normx = absx
end
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