From 5bea21e81ed516440e34e480f2c33ca41aa8c597 Mon Sep 17 00:00:00 2001
From: Bryan Newbold <bnewbold@robocracy.org>
Date: Mon, 20 Feb 2017 00:05:36 -0800
Subject: Import Upstream version 3a4

---
 grapheps.ps | 18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

(limited to 'grapheps.ps')

diff --git a/grapheps.ps b/grapheps.ps
index 95f200e..db3b8b1 100644
--- a/grapheps.ps
+++ b/grapheps.ps
@@ -185,10 +185,12 @@ plotdict begin
   /YSCL plotrect 3 get YRNG aload pop exch sub div def
   /XOFF XOFF plotrect 0 get XSCL div sub def
   /YOFF YOFF plotrect 1 get YSCL div sub def
-  /YTSCL plotrect 3 get YRNG aload pop exch sub find-tick-scale def
-  /YSTEP YTSCL 0 get 3 mod 0 eq {6} {8} ifelse 5 mul yuntrans def
-  /XTSCL plotrect 2 get XRNG aload pop exch sub find-tick-scale def
-  /XSTEP XTSCL 0 get 3 mod 0 eq {12} {10} ifelse 5 mul xuntrans def
+  /YTSCL plotrect 3 get YRNG aload pop exch sub abs find-tick-scale def
+  /YSTEP YTSCL 0 get 3 mod 0 eq {6} {8} ifelse 5 mul yuntrans
+	 YSCL sign mul def
+  /XTSCL plotrect 2 get XRNG aload pop exch sub abs find-tick-scale def
+  /XSTEP XTSCL 0 get 3 mod 0 eq {12} {10} ifelse 5 mul xuntrans
+         XSCL sign mul def
   /YSTEPH YSTEP 2 div def
   /XSTEPH XSTEP 2 div def
 } bind def
@@ -203,6 +205,8 @@ plotdict begin
 /yuntrans {YTSCL aload pop exch div mul} bind def
 /xuntrans {XTSCL aload pop exch div mul} bind def
 
+/sign {dup 0 lt {pop -1} {0 gt {1} {0} ifelse} ifelse} bind def
+
 /zero-in-range? {dup 0 get 0 le exch 1 get 0 ge and} bind def
 
 /y-axis
@@ -245,7 +249,7 @@ bind def
 } bind def
 
 % Given the width (or height) and the data-span, returns an array of
-% numerator and denominator (NUM DEN)
+% numerator and denominator [NUM DEN]
 %
 % NUM will be 1, 2, 3, 4, 5, 6, or 8 times a power of ten.
 % DEN will be a power of ten.
@@ -256,9 +260,9 @@ bind def
 /find-tick-scale
 {/DLTA exch def /ISIZ exch def
  /DEN 1 def
- {DLTA ISIZ le {exit} if /DEN DEN 10 mul def /ISIZ ISIZ 10 mul def} loop
+ {DLTA abs ISIZ le {exit} if /DEN DEN 10 mul def /ISIZ ISIZ 10 mul def} loop
  /NUM 1 def
- {DLTA 10 mul ISIZ ge {exit} if /NUM NUM 10 mul def /DLTA DLTA 10 mul def} loop
+ {DLTA abs 10 mul ISIZ ge {exit} if /NUM NUM 10 mul def /DLTA DLTA 10 mul def} loop
  [[8 6 5 4 3 2 1] {/MAX exch def MAX DLTA mul ISIZ le {MAX exit} if} forall
   NUM mul DEN]
 } bind def
-- 
cgit v1.2.3