math: Add math_number_all to enforce numbering all displayed math.

doc/ext/math.rst

@@ -28,6 +28,13 @@ Keep in mind that when you put math markup in **Python docstrings** read by
 :mod:`autodoc <sphinx.ext.autodoc>`, you either have to double all backslashes,
 or use Python raw strings (``r"raw"``).
 
+:mod:`.mathbase` provides the following config values:
+
+.. confval:: math_number_all
+
+   Set this option to ``True`` if you want all displayed math to be numbered.
+   The default is ``False``.
+
 :mod:`.mathbase` defines these new markup elements:
 
 .. rst:role:: math

sphinx/ext/imgmath.py

@@ -242,7 +242,8 @@ def html_visit_displaymath(self, node):
     if node['nowrap']:
         latex = node['latex']
     else:
-        latex = wrap_displaymath(node['latex'], None)
+        latex = wrap_displaymath(node['latex'], None,
+                                 self.builder.config.math_number_all)
     try:
         fname, depth = render_math(self, latex)
     except MathExtError as exc:

sphinx/ext/mathbase.py

@@ -28,7 +28,7 @@ class eqref(nodes.Inline, nodes.TextElement):
     pass
 
 
-def wrap_displaymath(math, label):
+def wrap_displaymath(math, label, numbering):
     parts = math.split('\n\n')
     ret = []
     for i, part in enumerate(parts):
@@ -38,7 +38,9 @@ def wrap_displaymath(math, label):
             ret.append('\\begin{split}%s\\end{split}' % part +
                        (label and '\\label{'+label+'}' or ''))
         else:
-            ret.append('\\begin{split}%s\\end{split}\\notag' % part)
+            ret.append(r'\begin{split}%s\end{split}' % part)
+            if not numbering:
+                ret.append(r'\notag')
     if not ret:
         return ''
     return '\\begin{gather}\n' + '\\\\'.join(ret) + '\n\\end{gather}'
@@ -116,7 +118,8 @@ def latex_visit_displaymath(self, node):
         self.body.append(node['latex'])
     else:
         label = node['label'] and node['docname'] + '-' + node['label'] or None
-        self.body.append(wrap_displaymath(node['latex'], label))
+        self.body.append(wrap_displaymath(node['latex'], label,
+                                          self.builder.config.math_number_all))
     raise nodes.SkipNode
 
 
@@ -194,10 +197,11 @@ def number_equations(app, doctree, docname):
     num = 0
     numbers = {}
     for node in doctree.traverse(displaymath):
-        if node['label'] is not None:
+        if node['label'] is not None or app.config.math_number_all:
             num += 1
             node['number'] = num
-            numbers[node['label']] = num
+            if node['label'] is not None:
+                numbers[node['label']] = num
         else:
             node['number'] = None
     for node in doctree.traverse(eqref):
@@ -208,6 +212,7 @@ def number_equations(app, doctree, docname):
 
 
 def setup_math(app, htmlinlinevisitors, htmldisplayvisitors):
+    app.add_config_value('math_number_all', False, 'html')
     app.add_node(math, override=True,
                  latex=(latex_visit_math, None),
                  text=(text_visit_math, None),

sphinx/ext/pngmath.py

@@ -213,7 +213,8 @@ def html_visit_displaymath(self, node):
     if node['nowrap']:
         latex = node['latex']
     else:
-        latex = wrap_displaymath(node['latex'], None)
+        latex = wrap_displaymath(node['latex'], None,
+                                 self.builder.config.math_number_all)
     try:
         fname, depth = render_math(self, latex)
     except MathExtError as exc: