From 5c8e3c92348a977449f76548d2193ed851115a73 Mon Sep 17 00:00:00 2001
From: Dimitri Lozeve <dimitri@lozeve.com>
Date: Fri, 30 Apr 2021 23:08:44 +0200
Subject: [PATCH] Support NaN values

---
 uniplot/lineplot.ss | 28 +++++++++++++++++-----------
 1 file changed, 17 insertions(+), 11 deletions(-)

diff --git a/uniplot/lineplot.ss b/uniplot/lineplot.ss
index 5daa4be..794af01 100644
--- a/uniplot/lineplot.ss
+++ b/uniplot/lineplot.ss
@@ -12,12 +12,18 @@
 
 (def +default-colors+ '(green blue red yellow cyan magenta white))
 
+(def (nanmin . rest)
+  (apply min (filter finite? rest)))
+
+(def (nanmax . rest)
+  (apply max (filter finite? rest)))
+
 (def (scale-fn lo hi)
   (lambda (x) (/ (- x lo) (- hi lo))))
 
 (def (draw-canvas xs ys x-scale-fn y-scale-fn width: (width 160) height: (height 80))
   (def canvas (make-braille-canvas (1+ height) (1+ width)))
-  (for ((x xs) (y ys))
+  (for ((x xs) (y ys) when (and (finite? x) (finite? y)))
     (braille-canvas-set! canvas
 			 (inexact->exact (floor (* height (y-scale-fn y))))
 			 (inexact->exact (floor (* width (x-scale-fn x))))
@@ -65,27 +71,27 @@
     (match lsts
       ([ys] (let ((xmin 0)
 		  (xmax (length ys))
-		  (ymin (apply min ys))
-		  (ymax (apply max ys)))
+		  (ymin (apply nanmin ys))
+		  (ymax (apply nanmax ys)))
 	      (values xmin xmax ymin ymax
 		      [(draw-canvas (iota (length ys)) ys
 				    (scale-fn xmin xmax)
 				    (scale-fn ymin ymax)
 				    width: width height: height)])))
-      ([xs ys] (let ((xmin (apply min xs))
-		     (xmax (apply max xs))
-		     (ymin (apply min ys))
-		     (ymax (apply max ys)))
+      ([xs ys] (let ((xmin (apply nanmin xs))
+		     (xmax (apply nanmax xs))
+		     (ymin (apply nanmin ys))
+		     (ymax (apply nanmax ys)))
 		 (values xmin xmax ymin ymax
 			 [(draw-canvas xs ys
 				       (scale-fn xmin xmax)
 				       (scale-fn ymin ymax)
 				       width: width height: height)])))
-      ([xs . yss] (let* ((xmin (apply min xs))
-			 (xmax (apply max xs))
+      ([xs . yss] (let* ((xmin (apply nanmin xs))
+			 (xmax (apply nanmax xs))
 			 (all-ys (flatten yss))
-			 (ymin (apply min all-ys))
-			 (ymax (apply max all-ys))
+			 (ymin (apply nanmin all-ys))
+			 (ymax (apply nanmax all-ys))
 			 (x-scale-fn (scale-fn xmin xmax))
 			 (y-scale-fn (scale-fn ymin ymax)))
 		    (values xmin xmax ymin ymax