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/glabax/glbencode.x | 66 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 66 insertions(+) create mode 100644 sys/gio/glabax/glbencode.x (limited to 'sys/gio/glabax/glbencode.x') diff --git a/sys/gio/glabax/glbencode.x b/sys/gio/glabax/glbencode.x new file mode 100644 index 00000000..cbed6875 --- /dev/null +++ b/sys/gio/glabax/glbencode.x @@ -0,0 +1,66 @@ +# Copyright(c) 1986 Association of Universities for Research in Astronomy Inc. + +include +include "glabax.h" + +# GLB_ENCODE -- Encode a floating point number as a character string for a +# tick label. We have to be careful how we do this, since on the one hand +# we want the most concise label possible (e.g., 500 not 500.00) but on the +# other we must provide enough precision to discriminate between ticks that +# are close together (e.g., 500.02 and 500.04). The extra information is +# given by the "ndigits" argument, which was calculated knowing the range +# and step at setup time. + +procedure glb_encode (x, out, maxch, format, step) + +real x # number to be encoded +char out[ARB] # output string +int maxch # max chars out +char format[ARB] # sprintf format +real step # tick spacing + +int ip, op +real nicex +define trim_ 91 + +begin + # Test for the zero tick, to avoid tick labels that look like the + # machine epsilon. + + if (abs (x / step) < TOL) + nicex = 0 + else + nicex = x + + # Encode number. + call sprintf (out, maxch, format) + call pargr (nicex) + + # Lop off any insignificant trailing zeros or periods. Watch out for + # trailing zeros in exponential format, e.g., "1.0E10". + + for (ip=1; out[ip] != EOS; ip=ip+1) + if (out[ip] == 'E' || out[ip] == 'D') + goto trim_ + + for (ip=ip-1; ip > 1 && out[ip] == '0'; ip=ip-1) + ; + if (ip > 1 && out[ip] == '.') + ip = ip - 1 + if (ip >= 1) + out[ip+1] = EOS + + # Lop off any insignificant leading zeros, but be sure to leave at + # least one digit. +trim_ + for (op=1; out[op] == '-' || out[op] == '+'; op=op+1) + ; + for (ip=op; out[ip] == '0' && out[ip+1] != EOS; ip=ip+1) + ; + while (out[ip] != EOS) { + out[op] = out[ip] + op = op + 1 + ip = ip + 1 + } + out[op] = EOS +end -- cgit