adds rcParam axes.formatter.useoffset

Addresses issue matplotlib#2400

added test for axes.formatter.useoffset rcparam

Author: tacaswell

doc/api/api_changes.rst

@@ -100,6 +100,11 @@ original location:
   (n, 1) arrays were returend unchanged.  This change makes the dimensions
   consistent in both cases.
 
+* Added the rcParam `axes.fromatter.useoffset` to control the default value
+  of `useOffset` in `ticker.ScalarFormatter`
+
+
+
 
 .. _changes_in_1_3:
 

doc/users/whats_new.rst

@@ -35,8 +35,8 @@ New plotting features
 Support for datetime axes in 2d plots
 `````````````````````````````````````
 Andrew Dawson added support for datetime axes to
-:func:`~matplotlib.pyplot.contour`, :func:`~matplotlib.pyplot.contourf`, 
-:func:`~matplotlib.pyplot.pcolormesh` and :func:`~matplotlib.pyplot.pcolor`. 
+:func:`~matplotlib.pyplot.contour`, :func:`~matplotlib.pyplot.contourf`,
+:func:`~matplotlib.pyplot.pcolormesh` and :func:`~matplotlib.pyplot.pcolor`.
 
 Support for additional spectrum types
 `````````````````````````````````````
@@ -83,13 +83,21 @@ conversion interfaces :class:`matplotlib.dates.DateConverter` and
 
 Configuration (rcParams)
 ------------------------
- 
+
 ``savefig.transparent`` added
 `````````````````````````````
-Controls whether figures are saved with a transparent 
+Controls whether figures are saved with a transparent
 background by default.  Previously `savefig` always defaulted
 to a non-transparent background.
 
+``axes.formatter.useoffset`` added
+``````````````````````````````````
+Controls the default value of `useOffset` in `ScalarFormatter`.  If
+`True` and the data range is much smaller than the data average, then
+an offset will be determined such that the tick labels are
+meaningful. If `False` then the full number will be formatted in all
+conditions.
+
 .. _whats-new-1-3:
 
 new in matplotlib-1.3

lib/matplotlib/rcsetup.py

@@ -592,6 +592,7 @@ def __call__(self, s):
     'axes.formatter.use_locale': [False, validate_bool],
                                # Use the current locale to format ticks
     'axes.formatter.use_mathtext': [False, validate_bool],
+    'axes.formatter.useoffset': [True, validate_bool],
     'axes.unicode_minus': [True, validate_bool],
     'axes.color_cycle': [['b', 'g', 'r', 'c', 'm', 'y', 'k'],
                          validate_colorlist],  # cycle of plot

lib/matplotlib/tests/test_ticker.py

@@ -2,11 +2,11 @@
                         unicode_literals)
 
 import six
-
+import nose.tools
 from nose.tools import assert_raises
 from numpy.testing import assert_almost_equal
 import numpy as np
-
+import matplotlib
 import matplotlib.ticker as mticker
 
 
@@ -50,6 +50,13 @@ def test_LogLocator():
     assert_almost_equal(loc.tick_values(1, 100), test_value)
 
 
+def test_use_offset():
+    for use_offset in [True, False]:
+        with matplotlib.rc_context({'axes.formatter.useoffset': use_offset}):
+            tmp_form = mticker.ScalarFormatter()
+            nose.tools.assert_equal(use_offset, tmp_form.get_useOffset())
+
+
 if __name__ == '__main__':
     import nose
     nose.runmodule(argv=['-s', '--with-doctest'], exit=False)

lib/matplotlib/ticker.py

@@ -356,11 +356,13 @@ class ScalarFormatter(Formatter):
 
     """
 
-    def __init__(self, useOffset=True, useMathText=None, useLocale=None):
+    def __init__(self, useOffset=None, useMathText=None, useLocale=None):
         # useOffset allows plotting small data ranges with large offsets: for
         # example: [1+1e-9,1+2e-9,1+3e-9] useMathText will render the offset
         # and scientific notation in mathtext
 
+        if useOffset is None:
+            useOffset = rcParams['axes.formatter.useoffset']
         self.set_useOffset(useOffset)
         self._usetex = rcParams['text.usetex']
         if useMathText is None:

matplotlibrc.template

@@ -234,7 +234,8 @@ backend      : %(backend)s
 #axes.labelweight    : normal  # weight of the x and y labels
 #axes.labelcolor     : black
 #axes.axisbelow      : False   # whether axis gridlines and ticks are below
-                              # the axes elements (lines, text, etc)
+                               # the axes elements (lines, text, etc)
+
 #axes.formatter.limits : -7, 7 # use scientific notation if log10
                                # of the axis range is smaller than the
                                # first or larger than the second
@@ -244,6 +245,12 @@ backend      : %(backend)s
                                    # separator in the fr_FR locale.
 #axes.formatter.use_mathtext : False # When True, use mathtext for scientific
                                      # notation.
+#axes.formatter.useoffset      : True    # If True, the tick label formatter 
+                                         # will default to labeling ticks relative 
+                                         # to an offset when the data range is very 
+                                         # small compared to the minimum absolute 
+                                         # value of the data.
+
 #axes.unicode_minus  : True    # use unicode for the minus symbol
                                # rather than hyphen.  See
                                # http://en.wikipedia.org/wiki/Plus_and_minus_signs#Character_codes