diff --git a/lib/matplotlib/projections/polar.py b/lib/matplotlib/projections/polar.py
index 3fbb4d2b9cfd..3243c76d8661 100644
--- a/lib/matplotlib/projections/polar.py
+++ b/lib/matplotlib/projections/polar.py
@@ -16,13 +16,18 @@
class PolarTransform(mtransforms.Transform):
- """
+ r"""
The base polar transform.
- This transform maps polar coordinates ``(theta, r)`` into Cartesian
- coordinates ``(x, y) = (r * cos(theta), r * sin(theta))`` (but does not
+ This transform maps polar coordinates :math:`\theta, r` into Cartesian
+ coordinates :math:`x, y = r \cos(\theta), r \sin(\theta)`
+ (but does not fully transform into Axes coordinates or
handle positioning in screen space).
+ This transformation is designed to be applied to data after any scaling
+ along the radial axis (e.g. log-scaling) has been applied to the input
+ data.
+
Path segments at a fixed radius are automatically transformed to circular
arcs as long as ``path._interpolation_steps > 1``.
"""
@@ -30,7 +35,7 @@ class PolarTransform(mtransforms.Transform):
input_dims = output_dims = 2
def __init__(self, axis=None, use_rmin=True,
- _apply_theta_transforms=True):
+ _apply_theta_transforms=True, *, scale_transform=None):
"""
Parameters
----------
@@ -46,12 +51,18 @@ def __init__(self, axis=None, use_rmin=True,
self._axis = axis
self._use_rmin = use_rmin
self._apply_theta_transforms = _apply_theta_transforms
+ self._scale_transform = scale_transform
__str__ = mtransforms._make_str_method(
"_axis",
use_rmin="_use_rmin",
_apply_theta_transforms="_apply_theta_transforms")
+ def _get_rorigin(self):
+ # Get lower r limit after being scaled by the radial scale transform
+ return self._scale_transform.transform(
+ (0, self._axis.get_rorigin()))[1]
+
def transform_non_affine(self, tr):
# docstring inherited
theta, r = np.transpose(tr)
@@ -61,7 +72,7 @@ def transform_non_affine(self, tr):
theta *= self._axis.get_theta_direction()
theta += self._axis.get_theta_offset()
if self._use_rmin and self._axis is not None:
- r = (r - self._axis.get_rorigin()) * self._axis.get_rsign()
+ r = (r - self._get_rorigin()) * self._axis.get_rsign()
r = np.where(r >= 0, r, np.nan)
return np.column_stack([r * np.cos(theta), r * np.sin(theta)])
@@ -85,7 +96,7 @@ def transform_path_non_affine(self, path):
# that behavior here.
last_td, td = np.rad2deg([last_t, t])
if self._use_rmin and self._axis is not None:
- r = ((r - self._axis.get_rorigin())
+ r = ((r - self._get_rorigin())
* self._axis.get_rsign())
if last_td <= td:
while td - last_td > 360:
@@ -877,7 +888,9 @@ def _set_lim_and_transforms(self):
# data. This one is aware of rmin
self.transProjection = self.PolarTransform(
self,
- _apply_theta_transforms=False)
+ _apply_theta_transforms=False,
+ scale_transform=self.transScale
+ )
# Add dependency on rorigin.
self.transProjection.set_children(self._originViewLim)
@@ -888,9 +901,25 @@ def _set_lim_and_transforms(self):
# The complete data transformation stack -- from data all the
# way to display coordinates
+ #
+ # 1. Remove any radial axis scaling (e.g. log scaling)
+ # 2. Shift data in the theta direction
+ # 3. Project the data from polar to cartesian values
+ # (with the origin in the same place)
+ # 4. Scale and translate the cartesian values to Axes coordinates
+ # (here the origin is moved to the lower left of the Axes)
+ # 5. Move and scale to fill the Axes
+ # 6. Convert from Axes coordinates to Figure coordinates
self.transData = (
- self.transScale + self.transShift + self.transProjection +
- (self.transProjectionAffine + self.transWedge + self.transAxes))
+ self.transScale +
+ self.transShift +
+ self.transProjection +
+ (
+ self.transProjectionAffine +
+ self.transWedge +
+ self.transAxes
+ )
+ )
# This is the transform for theta-axis ticks. It is
# equivalent to transData, except it always puts r == 0.0 and r == 1.0
diff --git a/lib/matplotlib/tests/baseline_images/test_polar/polar_log.png b/lib/matplotlib/tests/baseline_images/test_polar/polar_log.png
new file mode 100644
index 000000000000..ab8e20b482a5
Binary files /dev/null and b/lib/matplotlib/tests/baseline_images/test_polar/polar_log.png differ
diff --git a/lib/matplotlib/tests/test_polar.py b/lib/matplotlib/tests/test_polar.py
index 1bde5bcc1142..1f8e6a75baca 100644
--- a/lib/matplotlib/tests/test_polar.py
+++ b/lib/matplotlib/tests/test_polar.py
@@ -434,3 +434,15 @@ def test_cursor_precision():
assert ax.format_coord(2, 0) == "θ=0.6π (115°), r=0.000"
assert ax.format_coord(2, .1) == "θ=0.64π (115°), r=0.100"
assert ax.format_coord(2, 1) == "θ=0.637π (114.6°), r=1.000"
+
+
+@image_comparison(['polar_log.png'], style='default')
+def test_polar_log():
+ fig = plt.figure()
+ ax = fig.add_subplot(polar=True)
+
+ ax.set_rscale('log')
+ ax.set_rlim(1, 1000)
+
+ n = 100
+ ax.plot(np.linspace(0, 2 * np.pi, n), np.logspace(0, 2, n))
pFad - Phonifier reborn
Pfad - The Proxy pFad of © 2024 Garber Painting. All rights reserved.
Note: This service is not intended for secure transactions such as banking, social media, email, or purchasing. Use at your own risk. We assume no liability whatsoever for broken pages.
Alternative Proxies:
Alternative Proxy
pFad Proxy
pFad v3 Proxy
pFad v4 Proxy