White to Transparent Layer in matplotlib figure (SVG)-CodePudding

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CodePudding user response：

To achieve transition effect, You can plot one layer on top of Your existing figure with bicubic interpolation and custom color map.
First You have to create colormap having just two colors.
White color with alpha channel = 0 and other white with alpha channel = 1.
Then we add another figure filled with new color map from top to the bottom.

Here is code that does it:

import matplotlib.colors as mcolors import matplotlib.pyplot as plt import numpy as np fig = plt.figure(figsize=[6, 6]) x = np.arange(0, 100, 0.00001) y = np.sin(0.1 * np.pi * x) plt.plot(y) plt.axis('off') plt.gca().set_position([0, 0, 1, 1]) # Add new subplot on top of what is there already ax = fig.add_subplot() ax.axis('off') ax.set_position([0, 0, 1, 1]) # Create colormap of two white colors, one with alpha=0 and other one with alpha=1 colors = [(1, 1, 1, 0), (1, 1, 1, 1)] # Create new colormap from our two colors cmap = mcolors.LinearSegmentedColormap.from_list('mycmap', colors) # Use imshow with bicubic interpolation to create transition from top to bottom ax.imshow([[0., 0.], [1., 1.]], cmap=cmap, interpolation='bicubic', aspect='auto' ) # Save as .svg file plt.savefig("temp.svg", bbox_inches=0)

CodePudding user response：

You can adapt your code, to use as the example shown in the matplotlib documentation

More especifically, you can modify the gradient_bar function (which also uses the gradient_image function as)

def gradient_bar(ax, x, y, width=0.5, bottom=0): for left, top in zip(x, y): right = left width gradient_image( ax, #here you are forcing it to be from top to bottom extent=(left, right, top, bottom), #here you are forcing it to be vertical direction=0, cmap=plt.cm.Blues, cmap_range=(0, 1.0))