Merge pull request matplotlib#4733 from mdboom/4335-backport

Backport matplotlib#4335 to master

Author: tacaswell

doc/api/api_changes.rst

@@ -11,6 +11,12 @@ help figure out possible sources of the changes you are experiencing.
 For new features that were added to matplotlib, please see
 :ref:`whats-new`.
 
+Changes in 2.0.x
+================
+
+* The spacing commands in mathtext have been changed to more closely
+  match vanilla TeX.
+
 Changes in 1.4.x
 ================
 

lib/matplotlib/_mathtext_data.py

@@ -1946,7 +1946,6 @@
     'boxminus'                 : 8863,
     'equiv'                    : 8801,
     'Lleftarrow'               : 8666,
-    'thinspace'                : 8201,
     'll'                       : 8810,
     'Cup'                      : 8915,
     'measeq'                   : 8798,
@@ -2169,7 +2168,6 @@
     'cdots'                    : 8943,
     'hat'                      : 770,
     'eqgtr'                    : 8925,
-    'enspace'                  : 8194,
     'psi'                      : 968,
     'frown'                    : 8994,
     'acute'                    : 769,

lib/matplotlib/mathtext.py

@@ -2431,13 +2431,18 @@ def _make_space(self, percentage):
             self._em_width_cache[key] = width
         return Kern(width * percentage)
 
-    _space_widths = { r'\ '      : 0.3,
-                      r'\,'      : 0.4,
-                      r'\;'      : 0.8,
-                      r'\quad'   : 1.6,
-                      r'\qquad'  : 3.2,
-                      r'\!'      : -0.4,
-                      r'\/'      : 0.4 }
+    _space_widths = { r'\,'         : 0.16667,  # 3/18 em = 3 mu
+                      r'\thinspace' : 0.16667,  # 3/18 em = 3 mu
+                      r'\/'         : 0.16667,  # 3/18 em = 3 mu
+                      r'\>'         : 0.22222,  # 4/18 em = 4 mu
+                      r'\:'         : 0.22222,  # 4/18 em = 4 mu
+                      r'\;'         : 0.27778,  # 5/18 em = 5 mu
+                      r'\ '         : 0.33333,  # 6/18 em = 6 mu
+                      r'\enspace'   : 0.5,      # 9/18 em = 9 mu
+                      r'\quad'      : 1,        # 1 em = 18 mu
+                      r'\qquad'     : 2,        # 2 em = 36 mu
+                      r'\!'         : -0.16667, # -3/18 em = -3 mu
+                      }
     def space(self, s, loc, toks):
         assert(len(toks)==1)
         num = self._space_widths[toks[0]]