Add elinestyle property to errorbar (matplotlib#29879)

* Adding elinestyle property to errorbar and test case

* whitespaces in testcase

* Update lib/matplotlib/axes/_axes.py

Co-authored-by: Tim Hoffmann <2836374+timhoffm@users.noreply.github.com>

* Update set eb_line_style and fix formatting issues

* Remove extra line from test_axes

* Break line to reduce width in text_axes.py

* Remove trailing whitespaces from axes and test_axes.py

* Move elinestyle to the end of the list

* Shorten line length in axes.py

* accessing the correct property 'linestyle' in eb_line_style

* removing unused code

* Update lib/matplotlib/axes/_axes.pyi

Co-authored-by: Elliott Sales de Andrade <quantum.analyst@gmail.com>

* pyplot.py unwanted changes reverted

* Adding extra blank lines to fix style errors, and removing unnecessary asserts

* Updating test_axes.py tp test for dashed lines instead of default

* Style fix

---------

Co-authored-by: Tim Hoffmann <2836374+timhoffm@users.noreply.github.com>
Co-authored-by: Elliott Sales de Andrade <quantum.analyst@gmail.com>

Author: 3 people

lib/matplotlib/axes/_axes.py

@@ -3463,7 +3463,8 @@ def _errorevery_to_mask(x, errorevery):
     def errorbar(self, x, y, yerr=None, xerr=None,
                  fmt='', ecolor=None, elinewidth=None, capsize=None,
                  barsabove=False, lolims=False, uplims=False,
-                 xlolims=False, xuplims=False, errorevery=1, capthick=None,
+                 xlolims=False, xuplims=False, errorevery=1,
+                 capthick=None, elinestyle=None,
                  **kwargs):
         """
         Plot y versus x as lines and/or markers with attached errorbars.
@@ -3511,6 +3512,12 @@ def errorbar(self, x, y, yerr=None, xerr=None,
             The linewidth of the errorbar lines. If None, the linewidth of
             the current style is used.
 
+        elinestyle : str or tuple, default: 'solid'
+           The linestyle of the errorbar lines.
+           Valid values for linestyles include {'-', '--', '-.',
+            ':', '', (offset, on-off-seq)}. See `.Line2D.set_linestyle` for a
+            complete description.
+
         capsize : float, default: :rc:`errorbar.capsize`
             The length of the error bar caps in points.
 
@@ -3712,6 +3719,9 @@ def _upcast_err(err):
             if key in kwargs:
                 eb_lines_style[key] = kwargs[key]
 
+        if elinestyle is not None:
+            eb_lines_style['linestyle'] = elinestyle
+
         # Make the style dict for caps (the "hats").
         eb_cap_style = {**base_style, 'linestyle': 'none'}
         capsize = mpl._val_or_rc(capsize, "errorbar.capsize")

lib/matplotlib/axes/_axes.pyi

@@ -315,6 +315,7 @@ class Axes(_AxesBase):
         *,
         ecolor: ColorType | None = ...,
         elinewidth: float | None = ...,
+        elinestyle: LineStyleType | None = ...,
         capsize: float | None = ...,
         barsabove: bool = ...,
         lolims: bool | ArrayLike = ...,

lib/matplotlib/pyplot.py

@@ -3281,6 +3281,7 @@ def errorbar(
     xuplims: bool | ArrayLike = False,
     errorevery: int | tuple[int, int] = 1,
     capthick: float | None = None,
+    elinestyle: LineStyleType | None = None,
     *,
     data=None,
     **kwargs,
@@ -3301,6 +3302,7 @@ def errorbar(
         xuplims=xuplims,
         errorevery=errorevery,
         capthick=capthick,
+        elinestyle=elinestyle,
         **({"data": data} if data is not None else {}),
         **kwargs,
     )

lib/matplotlib/tests/test_axes.py

@@ -4526,6 +4526,14 @@ def test_errorbar_linewidth_type(elinewidth):
     plt.errorbar([1, 2, 3], [1, 2, 3], yerr=[1, 2, 3], elinewidth=elinewidth)
 
 
+def test_errorbar_linestyle_type():
+    eb = plt.errorbar([1, 2, 3], [1, 2, 3],
+                      yerr=[1, 2, 3], elinestyle='--')
+    errorlines = eb[-1][0]
+    errorlinestyle = errorlines.get_linestyle()
+    assert errorlinestyle == [(0, (6, 6))]
+
+
 @check_figures_equal()
 def test_errorbar_nan(fig_test, fig_ref):
     ax = fig_test.add_subplot()