Python图中的标签范围和颜色

时间:2017-04-01 19:26:39

标签: python matplotlib

在下面我试图绘制颜色和标签的点,每个j都会改变。我得到的是每个情侣(i,j)的不同颜色和图例中的一个标签:

import itertools
import numpy as np
import matplotlib.pyplot as plt

color_list = ["blue", "brown", "red", "black"]
g = itertools.cycle(color_list)

primes = (139,149,151,157,163,167)
for j in range(50, 300, 10):
    col = next(g)
    for k in (primes):
        for l in range(10000, 20000, 500):
            start = time.time()
            generator(j, k, l)
            end = time.time()
            plt.plot(l, end - start, linewidth = 2, marker='o', color=col)

编辑:使用我原来的问题更新了代码,因为我无法弄清楚Ernest + Arya的解决方案是否适用于这种情况。

3 个答案:

答案 0 :(得分:1)

您可以使用matplotlib cycler。设置要迭代的颜色列表,然后在j - 循环内,获取my_cycle.next()的颜色。然后将该颜色传递到您对plt.plot的调用中。

答案 1 :(得分:1)

i上的第二个循环不是没用吗?

import numpy as np
import matplotlib.pyplot as plt

for j in range (0, 2):
    x = np.arange(0,9,2)
    y = np.ones_like(x)*j + 0.5
    plt.plot(x,y, marker='o', label='$n = {j}$'.format(j=j))

plt.legend()    
plt.show()

enter image description here

更新问题的解决方案:

import itertools
import numpy as np
import matplotlib.pyplot as plt

color_list = ["blue", "brown", "red", "black"]
g = itertools.cycle(color_list)

for j in range (0, 2):
    col = next(g)
    x = np.arange(0,9,2)
    y = np.ones_like(x)*j + 0.5
    plt.plot(x,y, marker='o', color=col, label='$n = {j}$'.format(j=j))
plt.legend()  
plt.show()

enter image description here

第二次更新的解决方案;这个想法总是一样的:使用尽可能多的plt.plot()来电,因为你想拥有不同的颜色/图例条目。

import numpy as np
import matplotlib.pyplot as plt
import time

def generator(j,k,l):
    #some operation that takes a little time
    a = np.random.rand(k % 7, l-1000, j%13 )
    return a

color_list = ["blue", "brown", "red", "black"]

primes = (139,149,151,157,163,167)
for j in range(50, 300, 25):
    x = []; y = []
    for k in (primes):
        for l in range(10000, 20000, 1000):
            start = time.time()
            generator(j, k, l)
            end = time.time()
            x.append(l); y.append(end - start)
    plt.plot(x,y, ls="", marker='o', label='$n = {j}$'.format(j=j))

plt.legend()
plt.show()

enter image description here

答案 2 :(得分:1)

您可以使用sin或cos函数来控制颜色选择,并添加一个仅在j更改时更改的变量,以控制是否绘制新标签

import numpy as np
import matplotlib.pyplot as plt
import math

last_j = -1
z = 5
for j in range (0, z):
    color = ((math.sin(j)+1)/2,(math.cos(j+1)+1)/2,(math.cos(j)+1)/2)
    for i in range (0, 10, 2):
        if j == last_j:
            plt.plot(i + 0.5, j + 0.5, c=color, linewidth = 2, marker='o')
        else:
            plt.plot(i + 0.5, j + 0.5, c=color, linewidth = 2, marker='o', 
                label='$n = {j}$'.format(j=j))
        last_j = j

ax = plt.gca()
legend = ax.legend(loc = 'center right', shadow=True)

plt.show()

enter image description here