Fix mathtext tutorial for build with Sphinx 1.8.

anntzer · anntzer · commit a101de79650e · 2018-10-19T20:21:34.000+02:00
Sphinx 1.8 relies on MathJax for HTML math rendering, but a lot of
symbols provided by Matplotlib's mathtext come from somewhat obscure
packages that MathJax does not support.

Instead of trying to patch MathJax, just display the symbols as unicode.
diff --git a/doc/sphinxext/math_symbol_table.py b/doc/sphinxext/math_symbol_table.py
@@ -1,3 +1,6 @@
+from matplotlib import mathtext
+
+
 symbols = [
     ["Lower-case Greek",
      6,
@@ -112,9 +115,19 @@ def get_n(n, l):
         header = "    " + (('=' * max_width) + ' ') * columns
         lines.append(header)
         for part in get_n(columns, syms):
-            line = "    " + " ".join(
-                ":math:`{0}` ``{0}``".format(sym).rjust(max_width)
-                for sym in part)
+            line = (
+                "    " +
+                " ".join(
+                    "{} ``{}``".format(
+                        sym
+                        if not sym.startswith("\\")
+                        else sym[1:]
+                        if (sym[1:] in mathtext.Parser._overunder_functions
+                            or sym[1:] in mathtext.Parser._function_names)
+                        else chr(mathtext.tex2uni[sym[1:]]),
+                        sym)
+                    .rjust(max_width)
+                    for sym in part))
             lines.append(line)
         lines.append(header)
         lines.append('')
diff --git a/tutorials/text/mathtext.py b/tutorials/text/mathtext.py
@@ -179,9 +179,13 @@
 
     r's(t) = \mathcal{A}\/\sin(2 \omega t)'
 
+.. Here we cheat a bit: for HTML math rendering, Sphinx relies on MathJax which
+   doesn't actually support the italic correction (\/); instead, use a thin
+   space (\,) which is supported.
+
 .. math::
 
-    s(t) = \mathcal{A}\/\sin(2 \omega t)
+    s(t) = \mathcal{A}\,\sin(2 \omega t)
 
 The choices available with all fonts are:
 
