Matplotlib：如何根据图中文本的大小分配渐增的颜色阴影？

Question

我有一堆词频：

words = ['an', 'apple', 'in', 'a', 'tree']
counts = [23, 12, 45, 20, 9]

如何根据单词的值绘制matplotlib中的单词以及颜色变化平滑（例如cm.Blues）？

我的尝试是这样的：

import numpy as np
import matplotlib.pyplot as plt
plt.rc('font',**{'size':20, 'family':'fantasy'})

from collections import Counter
from matplotlib import colors as mcolors


words = ['an', 'apple', 'in', 'a', 'tree']
counts = [23,   12,      45,  20,   9]

plt.figure(figsize=(8,8))
c = list(mcolors.CSS4_COLORS.values())

for i in range(len(words)):
    x = np.random.uniform(low=0, high=1)
    y = np.random.uniform(low=0, high=1)
    plt.text(x, y, words[i], 
             size=counts[i]*2, 
             rotation=np.random.choice([-90, 0.0, 90]), 
             color=c[np.random.randint(0,len(c))])

plt.setp(plt.gca(), frame_on=False, xticks=(), yticks=())
plt.show()

颜色随机。

如何分配渐增的颜色深浅使这张图更直观？

Answer 1

CSS4_colors 是使用十六进制代码定义的 HTML 颜色。如果您想更改饱和度或亮度，这不是最佳选择。您可能想要使用 HSV 颜色模型。

因此您必须将颜色转换为 hsv，然后根据您的字数更改 s 或 v。

import numpy as np
import matplotlib.pyplot as plt
plt.rc('font',**{'size':20, 'family':'fantasy'})

from matplotlib import colors as mcolors

words = ['an', 'apple', 'in', 'a', 'tree']
counts = [23,   12,      45,  20,   9]
maxcounts = max(counts)
sat = [c / maxcounts for c in counts]

plt.figure(figsize=(8,8))

# convert colors to HSV
css4_colors = list(mcolors.CSS4_COLORS.values())
ncolors = len(c)
rgb = [mcolors.to_rgb(c) for c in css4_colors]
hsv = [mcolors.rgb_to_hsv(c) for c in rgb]


for i in range(len(words)):
    x = np.random.uniform(low=0, high=1)
    y = np.random.uniform(low=0, high=1)

    # select a color
    icolor = np.random.randint(0, ncolors)
    color = hsv[icolor]
    color[1] = sat[i] # here change saturation, index 1 or brightness, index 2 according to the counts list

    plt.text(x, y, words[i], 
             size=counts[i] * 2, 
             rotation=np.random.choice([-90, 0.0, 90]), 
             color=mcolors.hsv_to_rgb(color)) # don't forget to get back to rgb

plt.setp(plt.gca(), frame_on=False, xticks=(), yticks=())
plt.show()

编辑

好的，这是另一个版本，您 select 色调颜色（介于 0 和 1 之间）、亮度和仅更改饱和度。

根据自己的需要，可以根据计数改变亮度，保持饱和度不变

import numpy as np
import matplotlib.pyplot as plt
plt.rc('font',**{'size':20, 'family':'fantasy'})

from matplotlib import colors as mcolors

words = ['an', 'apple', 'in', 'a', 'tree']
counts = [23,   12,      45,  20,   9]
maxcounts = max(counts)
sat = [c / maxcounts for c in counts]

plt.figure(figsize=(8,8))

# select a hue value => define the color
hue = 0.6
# choose a brightness
brightness = 1

for i in range(len(words)):
    x = np.random.uniform(low=0, high=1)
    y = np.random.uniform(low=0, high=1)

    # select a color
    color = (hue, sat[i], brightness)

    plt.text(x, y, words[i],
             size=counts[i] * 2,
             rotation=np.random.choice([-90, 0.0, 90]),
             color=mcolors.hsv_to_rgb(color)) # don't forget to get back to rgb

plt.setp(plt.gca(), frame_on=False, xticks=(), yticks=())
plt.show()

Matplotlib：如何根据图中文本的大小分配渐增的颜色阴影？

Matplotlib: How to assign increasing shade of colors according to the size of text in a plot?

python

matplotlib

plot

python-ggplot