Avoid floating point error with maximum husl sat/lum (#2000)

* homogenization to use _color_to_rgb and normalization of husl_to_rgb output in [0,1]

* added better test to husl_to_rgb input and output

* Use numpy function and improve tests

Co-authored-by: Ivan Gonzalez <scratchmex@gmail.com>
(cherry picked from commit b47d843)

seaborn/palettes.py

@@ -382,7 +382,7 @@ def husl_palette(n_colors=6, h=.01, s=.9, l=.65):  # noqa
     hues *= 359
     s *= 99
     l *= 99  # noqa
-    palette = [husl.husl_to_rgb(h_i, s, l) for h_i in hues]
+    palette = [_color_to_rgb((h_i, s, l), input='husl') for h_i in hues]
     return _ColorPalette(palette)
 
 
@@ -469,8 +469,10 @@ def _color_to_rgb(color, input):
         color = colorsys.hls_to_rgb(*color)
     elif input == "husl":
         color = husl.husl_to_rgb(*color)
+        color = tuple(np.clip(color, 0, 1))
     elif input == "xkcd":
         color = xkcd_rgb[color]
+
     return color
 
 

seaborn/tests/test_palettes.py

@@ -194,8 +194,14 @@ def test_rgb_from_husl(self):
 
         color = 120, 50, 40
         rgb_got = palettes._color_to_rgb(color, "husl")
-        rgb_want = husl.husl_to_rgb(*color)
-        nt.assert_equal(rgb_got, rgb_want)
+        rgb_want = tuple(husl.husl_to_rgb(*color))
+        assert rgb_got == rgb_want
+
+        for h in range(0, 360):
+            color = h, 100, 100
+            rgb = palettes._color_to_rgb(color, "husl")
+            assert min(rgb) >= 0
+            assert max(rgb) <= 1
 
     def test_rgb_from_xkcd(self):