色を決めるのが面倒くさいとき、ありますよね。そのとき用の小ネタです。matplotlib で何かプロットを作ります。
%matplotlib inline
import matplotlib.pyplot as plt
import pandas as pd
import numpy as np
from sklearn.datasets.samples_generator import make_blobs
n_labels = 3
X, label = make_blobs(n_samples=100, centers=n_labels, n_features=2, cluster_std=np.random.rand(n_labels)*3)
df = pd.DataFrame(dict(x1=X[:,0], x2=X[:,1], label=label))
色を決めるときは、たとえばこのようにします。
colors = {0:'red', 1:'blue', 2:'green'}
fig, ax = plt.subplots()
grouped = df.groupby('label')
for key, group in grouped:
group.plot(ax=ax, kind='scatter', x='x1', y='x2', label=key, color=colors[key])
plt.legend(loc = 'right',
bbox_to_anchor = (0.7, 0.5, 0.5, 0.1),
borderaxespad = 0.0)
plt.grid()
plt.show()
色の数が３つくらいなら、以上のようにすればいいんですが、色が１０個とかもっとあると面倒臭いじゃないですか。ならばランダムに決めてしまいましょう。
import matplotlib
import random
colors = [cname for cname in matplotlib.colors.cnames.keys()]
random.shuffle(colors)
このようにすると、matplotlib で定義されている（名前のある）色が全列挙されます。（順番はランダムにシャッフルされています）
colors
['darkkhaki',
'black',
'blue',
'burlywood',
'gainsboro',
'mintcream',
'lightslategray',
'brown',
'cyan',
'mediumseagreen',
'darkolivegreen',
'darkmagenta',
'lightblue',
'mediumspringgreen',
'slategrey',
'mediumorchid',
'navajowhite',
'red',
'plum',
'mediumblue',
'indianred',
'hotpink',
'darkorange',
'coral',
'teal',
'sandybrown',
'lavender',
'khaki',
'lightsalmon',
'lightslategrey',
'azure',
'palegoldenrod',
'aliceblue',
'darkblue',
'lightsteelblue',
'chartreuse',
'silver',
'magenta',
'yellowgreen',
'crimson',
'aqua',
'linen',
'lightyellow',
'forestgreen',
'grey',
'darkorchid',
'floralwhite',
'lightgreen',
'lime',
'antiquewhite',
'dimgrey',
'ivory',
'gray',
'aquamarine',
'darkgrey',
'honeydew',
'powderblue',
'darkgreen',
'lightgrey',
'darkseagreen',
'darkgray',
'chocolate',
'beige',
'slateblue',
'cadetblue',
'seashell',
'olive',
'yellow',
'salmon',
'dodgerblue',
'peru',
'maroon',
'wheat',
'lightcyan',
'peachpuff',
'lightseagreen',
'royalblue',
'goldenrod',
'paleturquoise',
'purple',
'indigo',
'tan',
'lightgoldenrodyellow',
'lemonchiffon',
'darkturquoise',
'orange',
'orchid',
'lightskyblue',
'saddlebrown',
'lightgray',
'darksalmon',
'ghostwhite',
'limegreen',
'turquoise',
'navy',
'rosybrown',
'moccasin',
'papayawhip',
'green',
'greenyellow',
'cornflowerblue',
'darkcyan',
'blanchedalmond',
'deepskyblue',
'darkslateblue',
'midnightblue',
'snow',
'lightpink',
'darkslategrey',
'whitesmoke',
'oldlace',
'pink',
'mediumvioletred',
'mistyrose',
'sienna',
'blueviolet',
'fuchsia',
'tomato',
'dimgray',
'palevioletred',
'mediumpurple',
'rebeccapurple',
'lavenderblush',
'thistle',
'firebrick',
'springgreen',
'slategray',
'violet',
'skyblue',
'darkgoldenrod',
'darkviolet',
'deeppink',
'darkslategray',
'mediumturquoise',
'cornsilk',
'mediumaquamarine',
'steelblue',
'lightcoral',
'bisque',
'olivedrab',
'darkred',
'gold',
'white',
'palegreen',
'mediumslateblue',
'seagreen',
'lawngreen',
'orangered']
そうすれば、色の数が数十個に増えても怖くありません。
import numpy as np
from sklearn.datasets.samples_generator import make_blobs
n_labels = 10
X, label = make_blobs(n_samples=100, centers=n_labels, n_features=2, cluster_std=np.random.rand(n_labels)*3)
df = pd.DataFrame(dict(x1=X[:,0], x2=X[:,1], label=label))
fig, ax = plt.subplots()
grouped = df.groupby('label')
for key, group in grouped:
group.plot(ax=ax, kind='scatter', x='x1', y='x2', label=key, color=colors[key])
plt.legend(loc = 'right',
bbox_to_anchor = (0.7, 0.5, 0.5, 0.1),
borderaxespad = 0.0)
plt.grid()
plt.show()
色合いが気に入らなければ、
random.shuffle(colors)
で色を並び替えて、納得いくまで繰り返せばいいです。気に入った配色になれば、colors の中身を確認してそれを再利用すればいいです。
fig, ax = plt.subplots()
grouped = df.groupby('label')
for key, group in grouped:
group.plot(ax=ax, kind='scatter', x='x1', y='x2', label=key, color=colors[key])
plt.legend(loc = 'right',
bbox_to_anchor = (0.7, 0.5, 0.5, 0.1),
borderaxespad = 0.0)
plt.grid()
plt.show()
サンプルコード
色を自動で決めるコードを追記しました。
# coding: utf-8
# In[1]:
import random
import matplotlib
import matplotlib.pyplot as plt
edge_colors = ["brown", "black", "red", "blue", "green"]
looks = [
[cname, 0, edge_colors[i % len(edge_colors)], i]
for i, cname in enumerate(matplotlib.colors.cnames.keys())
]
random.shuffle(looks)
get_ipython().run_line_magic("matplotlib", "inline")
plt.figure(figsize=(10, 10), dpi=200)
index = 0
X = [random.random() for x in range(10000)]
Y = [random.random() for x in range(10000)]
plt.scatter(
X,
Y,
c=looks[index][0],
linewidths=looks[index][1],
edgecolors=looks[index][2],
alpha=0.5,
label="data1",
)
index = 1
X = [random.random() for x in range(500)]
Y = [random.random() for x in range(500)]
plt.scatter(
X, Y, c=looks[index][0], linewidths=2, edgecolors="black", alpha=0.5, label="data2"
)
index = 2
X = [random.random() for x in range(100)]
Y = [random.random() for x in range(100)]
plt.scatter(
X, Y, c=looks[index][0], linewidths=2, edgecolors="red", alpha=0.5, label="data3"
)
index = 3
X = [random.random() for x in range(100)]
Y = [random.random() for x in range(100)]
plt.scatter(
X, Y, c=looks[index][0], linewidths=2, edgecolors="blue", alpha=0.5, label="data4"
)
index = 4
X = [random.random() for x in range(100)]
Y = [random.random() for x in range(100)]
plt.scatter(
X, Y, c=looks[index][0], linewidths=2, edgecolors="green", alpha=0.5, label="data5"
)
plt.legend()
plt.grid()
plt.show()
looks
[['palegoldenrod', 0, 'blue', 108],
['red', 0, 'brown', 120],
['coral', 0, 'black', 16],
['greenyellow', 0, 'brown', 55],
['cyan', 0, 'brown', 20],
['mediumseagreen', 0, 'black', 91],
['hotpink', 0, 'blue', 58],
['khaki', 0, 'red', 62],
['green', 0, 'green', 54],
['mediumslateblue', 0, 'red', 92],
['olive', 0, 'blue', 103],
['darkgray', 0, 'green', 24],
['thistle', 0, 'green', 139],
['moccasin', 0, 'green', 99],
['indigo', 0, 'brown', 60],
['darkslategrey', 0, 'red', 37],
['lightslategrey', 0, 'green', 79],
['darkslateblue', 0, 'brown', 35],
['firebrick', 0, 'brown', 45],
['chartreuse', 0, 'green', 14],
['mediumblue', 0, 'blue', 88],
['maroon', 0, 'black', 86],
['lightseagreen', 0, 'black', 76],
['goldenrod', 0, 'red', 52],
['cadetblue', 0, 'blue', 13],
['orchid', 0, 'red', 107],
['mediumpurple', 0, 'brown', 90],
['bisque', 0, 'black', 6],
['lightgoldenrodyellow', 0, 'brown', 70],
['navajowhite', 0, 'brown', 100],
['lightsalmon', 0, 'brown', 75],
['yellow', 0, 'black', 146],
['dimgray', 0, 'red', 42],
['rosybrown', 0, 'black', 121],
['tan', 0, 'red', 137],
['honeydew', 0, 'red', 57],
['salmon', 0, 'green', 124],
['darkblue', 0, 'black', 21],
['orangered', 0, 'black', 106],
['navy', 0, 'black', 101],
['papayawhip', 0, 'red', 112],
['darkorchid', 0, 'black', 31],
['lightblue', 0, 'red', 67],
['blueviolet', 0, 'brown', 10],
['lightsteelblue', 0, 'brown', 80],
['cornflowerblue', 0, 'red', 17],
['powderblue', 0, 'red', 117],
['magenta', 0, 'brown', 85],
['seagreen', 0, 'black', 126],
['royalblue', 0, 'red', 122],
['floralwhite', 0, 'black', 46],
['antiquewhite', 0, 'black', 1],
['lightslategray', 0, 'blue', 78],
['darkslategray', 0, 'black', 36],
['violet', 0, 'red', 142],
['midnightblue', 0, 'black', 96],
['orange', 0, 'brown', 105],
['skyblue', 0, 'brown', 130],
['deeppink', 0, 'brown', 40],
['olivedrab', 0, 'green', 104],
['turquoise', 0, 'black', 141],
['lightyellow', 0, 'black', 81],
['steelblue', 0, 'black', 136],
['lavenderblush', 0, 'green', 64],
['slateblue', 0, 'black', 131],
['dodgerblue', 0, 'green', 44],
['beige', 0, 'brown', 5],
['darkred', 0, 'red', 32],
['snow', 0, 'green', 134],
['darkgreen', 0, 'brown', 25],
['aliceblue', 0, 'brown', 0],
['ivory', 0, 'black', 61],
['mediumorchid', 0, 'green', 89],
['mediumaquamarine', 0, 'red', 87],
['plum', 0, 'black', 116],
['rebeccapurple', 0, 'green', 119],
['darkolivegreen', 0, 'green', 29],
['brown', 0, 'black', 11],
['lightcyan', 0, 'green', 69],
['sienna', 0, 'blue', 128],
['ghostwhite', 0, 'brown', 50],
['blue', 0, 'green', 9],
['teal', 0, 'blue', 138],
['lightgreen', 0, 'red', 72],
['tomato', 0, 'brown', 140],
['chocolate', 0, 'brown', 15],
['lightgrey', 0, 'blue', 73],
['deepskyblue', 0, 'black', 41],
['mediumspringgreen', 0, 'blue', 93],
['mintcream', 0, 'red', 97],
['crimson', 0, 'green', 19],
['palegreen', 0, 'green', 109],
['azure', 0, 'green', 4],
['darkgoldenrod', 0, 'blue', 23],
['dimgrey', 0, 'blue', 43],
['darkcyan', 0, 'red', 22],
['darkmagenta', 0, 'blue', 28],
['peru', 0, 'green', 114],
['paleturquoise', 0, 'brown', 110],
['lightskyblue', 0, 'red', 77],
['seashell', 0, 'red', 127],
['lime', 0, 'red', 82],
['cornsilk', 0, 'blue', 18],
['springgreen', 0, 'brown', 135],
['white', 0, 'green', 144],
['lightgray', 0, 'black', 71],
['gray', 0, 'blue', 53],
['grey', 0, 'black', 56],
['mediumvioletred', 0, 'brown', 95],
['lavender', 0, 'blue', 63],
['aqua', 0, 'red', 2],
['darkviolet', 0, 'green', 39],
['lightpink', 0, 'green', 74],
['lightcoral', 0, 'blue', 68],
['silver', 0, 'green', 129],
['gainsboro', 0, 'green', 49],
['saddlebrown', 0, 'blue', 123],
['darkorange', 0, 'brown', 30],
['forestgreen', 0, 'red', 47],
['purple', 0, 'blue', 118],
['peachpuff', 0, 'blue', 113],
['slategrey', 0, 'blue', 133],
['whitesmoke', 0, 'brown', 145],
['darkturquoise', 0, 'blue', 38],
['palevioletred', 0, 'black', 111],
['darkgrey', 0, 'black', 26],
['darkseagreen', 0, 'green', 34],
['lemonchiffon', 0, 'black', 66],
['fuchsia', 0, 'blue', 48],
['sandybrown', 0, 'brown', 125],
['indianred', 0, 'green', 59],
['pink', 0, 'brown', 115],
['aquamarine', 0, 'blue', 3],
['mistyrose', 0, 'blue', 98],
['mediumturquoise', 0, 'green', 94],
['yellowgreen', 0, 'red', 147],
['darkkhaki', 0, 'red', 27],
['oldlace', 0, 'red', 102],
['gold', 0, 'black', 51],
['black', 0, 'red', 7],
['lawngreen', 0, 'brown', 65],
['darksalmon', 0, 'blue', 33],
['linen', 0, 'green', 84],
['burlywood', 0, 'red', 12],
['limegreen', 0, 'blue', 83],
['blanchedalmond', 0, 'blue', 8],
['slategray', 0, 'red', 132],
['wheat', 0, 'blue', 143]]