diff --git a/lib/matplotlib/artist.py b/lib/matplotlib/artist.py index 2d71ed6e92c8..aa2fa15ae831 100644 --- a/lib/matplotlib/artist.py +++ b/lib/matplotlib/artist.py @@ -12,6 +12,7 @@ import matplotlib as mpl from . import _api, cbook +from .colors import BoundaryNorm from .cm import ScalarMappable from .path import Path from .transforms import (Bbox, IdentityTransform, Transform, TransformedBbox, @@ -1280,10 +1281,20 @@ def format_cursor_data(self, data): return "[]" normed = self.norm(data) if np.isfinite(normed): - # Midpoints of neighboring color intervals. - neighbors = self.norm.inverse( - (int(self.norm(data) * n) + np.array([0, 1])) / n) - delta = abs(neighbors - data).max() + if isinstance(self.norm, BoundaryNorm): + # not an invertible normalization mapping + cur_idx = np.argmin(np.abs(self.norm.boundaries - data)) + neigh_idx = max(0, cur_idx - 1) + # use max diff to prevent delta == 0 + delta = np.diff( + self.norm.boundaries[neigh_idx:cur_idx + 2] + ).max() + + else: + # Midpoints of neighboring color intervals. + neighbors = self.norm.inverse( + (int(normed * n) + np.array([0, 1])) / n) + delta = abs(neighbors - data).max() g_sig_digits = cbook._g_sig_digits(data, delta) else: g_sig_digits = 3 # Consistent with default below. diff --git a/lib/matplotlib/tests/test_artist.py b/lib/matplotlib/tests/test_artist.py index 74c58d34d991..f5b4e6f84793 100644 --- a/lib/matplotlib/tests/test_artist.py +++ b/lib/matplotlib/tests/test_artist.py @@ -5,6 +5,8 @@ import pytest +from matplotlib import cm +import matplotlib.colors as mcolors import matplotlib.pyplot as plt import matplotlib.patches as mpatches import matplotlib.lines as mlines @@ -374,3 +376,164 @@ class MyArtist4(MyArtist3): pass assert MyArtist4.set is MyArtist3.set + + +def test_format_cursor_data_BoundaryNorm(): + """Test if cursor data is correct when using BoundaryNorm.""" + X = np.empty((3, 3)) + X[0, 0] = 0.9 + X[0, 1] = 0.99 + X[0, 2] = 0.999 + X[1, 0] = -1 + X[1, 1] = 0 + X[1, 2] = 1 + X[2, 0] = 0.09 + X[2, 1] = 0.009 + X[2, 2] = 0.0009 + + # map range -1..1 to 0..256 in 0.1 steps + fig, ax = plt.subplots() + fig.suptitle("-1..1 to 0..256 in 0.1") + norm = mcolors.BoundaryNorm(np.linspace(-1, 1, 20), 256) + img = ax.imshow(X, cmap='RdBu_r', norm=norm) + + labels_list = [ + "[0.9]", + "[1.]", + "[1.]", + "[-1.0]", + "[0.0]", + "[1.0]", + "[0.09]", + "[0.009]", + "[0.0009]", + ] + for v, label in zip(X.flat, labels_list): + # label = "[{:-#.{}g}]".format(v, cbook._g_sig_digits(v, 0.1)) + assert img.format_cursor_data(v) == label + + plt.close() + + # map range -1..1 to 0..256 in 0.01 steps + fig, ax = plt.subplots() + fig.suptitle("-1..1 to 0..256 in 0.01") + cmap = cm.get_cmap('RdBu_r', 200) + norm = mcolors.BoundaryNorm(np.linspace(-1, 1, 200), 200) + img = ax.imshow(X, cmap=cmap, norm=norm) + + labels_list = [ + "[0.90]", + "[0.99]", + "[1.0]", + "[-1.00]", + "[0.00]", + "[1.00]", + "[0.09]", + "[0.009]", + "[0.0009]", + ] + for v, label in zip(X.flat, labels_list): + # label = "[{:-#.{}g}]".format(v, cbook._g_sig_digits(v, 0.01)) + assert img.format_cursor_data(v) == label + + plt.close() + + # map range -1..1 to 0..256 in 0.01 steps + fig, ax = plt.subplots() + fig.suptitle("-1..1 to 0..256 in 0.001") + cmap = cm.get_cmap('RdBu_r', 2000) + norm = mcolors.BoundaryNorm(np.linspace(-1, 1, 2000), 2000) + img = ax.imshow(X, cmap=cmap, norm=norm) + + labels_list = [ + "[0.900]", + "[0.990]", + "[0.999]", + "[-1.000]", + "[0.000]", + "[1.000]", + "[0.090]", + "[0.009]", + "[0.0009]", + ] + for v, label in zip(X.flat, labels_list): + # label = "[{:-#.{}g}]".format(v, cbook._g_sig_digits(v, 0.001)) + assert img.format_cursor_data(v) == label + + plt.close() + + # different testing data set with + # out of bounds values for 0..1 range + X = np.empty((7, 1)) + X[0] = -1.0 + X[1] = 0.0 + X[2] = 0.1 + X[3] = 0.5 + X[4] = 0.9 + X[5] = 1.0 + X[6] = 2.0 + + labels_list = [ + "[-1.0]", + "[0.0]", + "[0.1]", + "[0.5]", + "[0.9]", + "[1.0]", + "[2.0]", + ] + + fig, ax = plt.subplots() + fig.suptitle("noclip, neither") + norm = mcolors.BoundaryNorm( + np.linspace(0, 1, 4, endpoint=True), 256, clip=False, extend='neither') + img = ax.imshow(X, cmap='RdBu_r', norm=norm) + for v, label in zip(X.flat, labels_list): + # label = "[{:-#.{}g}]".format(v, cbook._g_sig_digits(v, 0.33)) + assert img.format_cursor_data(v) == label + + plt.close() + + fig, ax = plt.subplots() + fig.suptitle("noclip, min") + norm = mcolors.BoundaryNorm( + np.linspace(0, 1, 4, endpoint=True), 256, clip=False, extend='min') + img = ax.imshow(X, cmap='RdBu_r', norm=norm) + for v, label in zip(X.flat, labels_list): + # label = "[{:-#.{}g}]".format(v, cbook._g_sig_digits(v, 0.33)) + assert img.format_cursor_data(v) == label + + plt.close() + + fig, ax = plt.subplots() + fig.suptitle("noclip, max") + norm = mcolors.BoundaryNorm( + np.linspace(0, 1, 4, endpoint=True), 256, clip=False, extend='max') + img = ax.imshow(X, cmap='RdBu_r', norm=norm) + for v, label in zip(X.flat, labels_list): + # label = "[{:-#.{}g}]".format(v, cbook._g_sig_digits(v, 0.33)) + assert img.format_cursor_data(v) == label + + plt.close() + + fig, ax = plt.subplots() + fig.suptitle("noclip, both") + norm = mcolors.BoundaryNorm( + np.linspace(0, 1, 4, endpoint=True), 256, clip=False, extend='both') + img = ax.imshow(X, cmap='RdBu_r', norm=norm) + for v, label in zip(X.flat, labels_list): + # label = "[{:-#.{}g}]".format(v, cbook._g_sig_digits(v, 0.33)) + assert img.format_cursor_data(v) == label + + plt.close() + + fig, ax = plt.subplots() + fig.suptitle("clip, neither") + norm = mcolors.BoundaryNorm( + np.linspace(0, 1, 4, endpoint=True), 256, clip=True, extend='neither') + img = ax.imshow(X, cmap='RdBu_r', norm=norm) + for v, label in zip(X.flat, labels_list): + # label = "[{:-#.{}g}]".format(v, cbook._g_sig_digits(v, 0.33)) + assert img.format_cursor_data(v) == label + + plt.close()