May 25, 2020 · Mar 25, 2020 · Mar 30, 2020 · Mar 30, 2020 · Mar 30, 2020 · Mar 30, 2020
diff --git a/lib/matplotlib/collections.py b/lib/matplotlib/collections.py
        """Update colors from the scalar mappable array, if it is not None."""
        if self._A is None:
            return
        if self._A.ndim > 1:
        # QuadMesh can map 2d arrays
        if self._A.ndim > 1 and not isinstance(self, QuadMesh):
            raise ValueError('Collections can only map rank 1 arrays')
        if not self._check_update("array"):
            return
        else:
            renderer.draw_quad_mesh(
                gc, transform.frozen(), self._meshWidth, self._meshHeight,
                coordinates, offsets, transOffset, self.get_facecolor(),
                self._antialiased, self.get_edgecolors())
                coordinates, offsets, transOffset,
                # Backends expect flattened rgba arrays (n*m, 4) for fc and ec
                self.get_facecolor().reshape((-1, 4)),
                self._antialiased, self.get_edgecolors().reshape((-1, 4)))
        gc.restore()
        renderer.close_group(self.__class__.__name__)
        self.stale = False
diff --git a/lib/matplotlib/tests/test_collections.py b/lib/matplotlib/tests/test_collections.py
    ax.scatter(0, 0)
    np.testing.assert_allclose(ax.get_ylim(), [-0.06, 0.06])
    np.testing.assert_allclose(ax.get_xlim(), [-0.06, 0.06])


 def test_quadmesh_set_array():
    x = np.arange(4)
    y = np.arange(4)
    z = np.arange(9).reshape((3, 3))
    fig, ax = plt.subplots()
    coll = ax.pcolormesh(x, y, np.ones(z.shape))
    # Test that the collection is able to update with a 2d array
    coll.set_array(z)
    fig.canvas.draw()
    assert np.array_equal(coll.get_array(), z)

    # Check that pre-flattened arrays work too
    coll.set_array(np.ones(9))
    fig.canvas.draw()
    assert np.array_equal(coll.get_array(), np.ones(9))
Original file line number	Diff line number	Diff line change
Expand Up		@@ -779,7 +779,8 @@ def update_scalarmappable(self):
		"""Update colors from the scalar mappable array, if it is not None."""
		if self._A is None:
		return
		if self._A.ndim > 1:
		# QuadMesh can map 2d arrays
		if self._A.ndim > 1 and not isinstance(self, QuadMesh):
Copy link Member tacaswellMar 30, 2020 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others.Learn more. Could we do the raveling here as ifisinstance(self,QuadMesh):self._A=self._A.ravel()else:raiseValueError(...) It keeps everything a bit more consistent shape wise? Copy link ContributorAuthor greglucasMar 30, 2020 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others.Learn more. That's actually what I had originally, but force-pushed over. The downside to it is if someone calls get_array() it is a different shape returned, which could cause confusion? Copy link Member tacaswellMar 30, 2020 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others.Learn more. That is a fair point, but I am also worried about the shape stability of people who have code written against QuadMesh who are now going to be suprised that sometimes they get back 2d data. Copy link ContributorAuthor greglucasMar 30, 2020 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others.Learn more. That should only happen if they pass in 2d data, which was not possible before. So, I think all the before cases were 1d inputs and will return 1d inputs still. This is really for my selfish future motivation of wanting to call update animations without forgetting to ravel() and get the ValueError thrown my way. I completely agree though, it does add another layer of potential confusion and that should be weighed on pros/cons. Copy link Member tacaswellMar 30, 2020 Choose a reason for hiding this comment The reason will be displayed to describe this comment to others.Learn more. I am worried about the (hypothetical) that someone has written a function that takes in a`QuadMesh`, uses`get_array()`, and assumes 1d data. If we do the reshaping at the last minute then that assumption is no longer valid, but there is no way for the function author to reasonably know. I do see both sides of this and neither is obviously better.
		raise ValueError('Collections can only map rank 1 arrays')
		if not self._check_update("array"):
		return
Expand DownExpand Up		@@ -2044,8 +2045,10 @@ def draw(self, renderer):
		else:
		renderer.draw_quad_mesh(
		gc, transform.frozen(), self._meshWidth, self._meshHeight,
		coordinates, offsets, transOffset, self.get_facecolor(),
		self._antialiased, self.get_edgecolors())
		coordinates, offsets, transOffset,
		# Backends expect flattened rgba arrays (n*m, 4) for fc and ec
		self.get_facecolor().reshape((-1, 4)),
		self._antialiased, self.get_edgecolors().reshape((-1, 4)))
		gc.restore()
		renderer.close_group(self.__class__.__name__)
		self.stale = False
Expand Down
Original file line number	Diff line number	Diff line change
Expand Up		@@ -637,3 +637,20 @@ def test_singleton_autolim():
		ax.scatter(0, 0)
		np.testing.assert_allclose(ax.get_ylim(), [-0.06, 0.06])
		np.testing.assert_allclose(ax.get_xlim(), [-0.06, 0.06])


		def test_quadmesh_set_array():
		x = np.arange(4)
		y = np.arange(4)
		z = np.arange(9).reshape((3, 3))
		fig, ax = plt.subplots()
		coll = ax.pcolormesh(x, y, np.ones(z.shape))
		# Test that the collection is able to update with a 2d array
		coll.set_array(z)
		fig.canvas.draw()
		assert np.array_equal(coll.get_array(), z)

		# Check that pre-flattened arrays work too
		coll.set_array(np.ones(9))
		fig.canvas.draw()
		assert np.array_equal(coll.get_array(), np.ones(9))