From fa080de7afc95aa1c19a6e6fc0e0708ced2eadc4 Mon Sep 17 00:00:00 2001 From: Joseph Hunkeler Date: Wed, 8 Jul 2015 20:46:52 -0400 Subject: Initial commit --- sys/gio/fpnormd.x | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) create mode 100644 sys/gio/fpnormd.x (limited to 'sys/gio/fpnormd.x') diff --git a/sys/gio/fpnormd.x b/sys/gio/fpnormd.x new file mode 100644 index 00000000..067ef1e0 --- /dev/null +++ b/sys/gio/fpnormd.x @@ -0,0 +1,40 @@ +# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc. + +include + +# 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 -- cgit