matplotlib · timhoffm · Mar 3, 2019 · Mar 3, 2019
diff --git a/doc/users/next_whats_new/engformatter_usetex_usemathtext.rst b/doc/users/next_whats_new/engformatter_usetex_usemathtext.rst
@@ -0,0 +1,14 @@
+`EngFormatter` now accepts `usetex`, `useMathText` as keyword only arguments
+````````````````````````````````````````````````````````````````````````````
+
+A public API has been added to `EngFormatter` to control how the numbers in the
+ ticklabels will be rendered. By default, ``useMathText`` evaluates to
+ ``rcParams['axes.formatter.use_mathtext']`` and ``usetex`` evaluates to
+ ``rcParams['text.usetex']``.
+
+If either is ``True`` then  the numbers will be encapsulated by ``$`` signs.
+ When using ``TeX`` this implies that the numbers will be shown in TeX's math
+ font. When using mathtext, the ``$`` signs around numbers will ensure unicode
+ rendering (as implied by mathtext). This will make sure that the minus signs
+ in the ticks are rendered as the unicode-minus (U+2212) when using mathtext
+ (without relying on the ``fix_minus`` method).
diff --git a/lib/matplotlib/tests/test_ticker.py b/lib/matplotlib/tests/test_ticker.py
@@ -788,6 +788,20 @@ def test_params(self, input, expected):
                 assert _formatter(input) == _exp_output
 
 
+def test_engformatter_usetex_useMathText():
+    fig, ax = plt.subplots()
+    ax.plot([0, 500, 1000], [0, 500, 1000])
+    ax.set_xticks([0, 500, 1000])
+    for formatter in (mticker.EngFormatter(usetex=True),
+                      mticker.EngFormatter(useMathText=True)):
+        ax.xaxis.set_major_formatter(formatter)
+        fig.canvas.draw()
+        x_tick_label_text = [labl.get_text() for labl in ax.get_xticklabels()]
+        # Checking if the dollar `$` signs have been inserted around numbers
+        # in tick labels.
+        assert x_tick_label_text == ['$0$', '$500$', '$1$ k']
+
+
 class TestPercentFormatter(object):
     percent_data = [
         # Check explicitly set decimals over different intervals and values

diff --git a/lib/matplotlib/tests/test_usetex.py b/lib/matplotlib/tests/test_usetex.py
@@ -32,18 +32,3 @@ def test_usetex():
             fontsize=24)
     ax.set_xticks([])
     ax.set_yticks([])
-
-
-@needs_usetex
-def test_usetex_engformatter():
-    matplotlib.rcParams['text.usetex'] = True
-    fig, ax = plt.subplots()
-    ax.plot([0, 500, 1000], [0, 500, 1000])
-    ax.set_xticks([0, 500, 1000])
-    formatter = EngFormatter()
-    ax.xaxis.set_major_formatter(formatter)
-    fig.canvas.draw()
-    x_tick_label_text = [label.get_text() for label in ax.get_xticklabels()]
-    # Checking if the dollar `$` signs have been inserted around numbers
-    # in tick label text.
-    assert x_tick_label_text == ['$0$', '$500$', '$1$ k']
diff --git a/lib/matplotlib/ticker.py b/lib/matplotlib/ticker.py
@@ -1208,7 +1208,8 @@ class EngFormatter(Formatter):
          24: "Y"
     }
 
-    def __init__(self, unit="", places=None, sep=" "):
+    def __init__(self, unit="", places=None, sep=" ", *, usetex=None,
+                 useMathText=None):
         """
         Parameters
         ----------
@@ -1234,10 +1235,42 @@ def __init__(self, unit="", places=None, sep=" "):
             * ``sep="\\N{THIN SPACE}"`` (``U+2009``);
             * ``sep="\\N{NARROW NO-BREAK SPACE}"`` (``U+202F``);
             * ``sep="\\N{NO-BREAK SPACE}"`` (``U+00A0``).
+
+        usetex : bool (default: None)
+            To enable/disable the use of TeX's math mode for rendering the
+            numbers in the formatter.
+
+        useMathText : bool (default: None)
+            To enable/disable the use mathtext for rendering the numbers in
+            the formatter.
         """
         self.unit = unit
         self.places = places
         self.sep = sep
+        self.set_usetex(usetex)
+        self.set_useMathText(useMathText)
+
+    def get_usetex(self):
+        return self._usetex
+
+    def set_usetex(self, val):
+        if val is None:
+            self._usetex = rcParams['text.usetex']
+        else:
+            self._usetex = val
+
+    usetex = property(fget=get_usetex, fset=set_usetex)
+
+    def get_useMathText(self):
+        return self._useMathText
+
+    def set_useMathText(self, val):
+        if val is None:
+            self._useMathText = rcParams['axes.formatter.use_mathtext']
+        else:
+            self._useMathText = val
+
+    useMathText = property(fget=get_useMathText, fset=set_useMathText)
 
     def __call__(self, x, pos=None):
         s = "%s%s" % (self.format_eng(x), self.unit)
@@ -1289,7 +1322,7 @@ def format_eng(self, num):
             pow10 += 3
 
         prefix = self.ENG_PREFIXES[int(pow10)]
-        if rcParams['text.usetex']:
+        if self._usetex or self._useMathText:
             formatted = "${mant:{fmt}}${sep}{prefix}".format(
                 mant=mant, sep=self.sep, prefix=prefix, fmt=fmt)
         else: