如何为多彩色散点图创建图例而不是颜色条？

Question

我想在多个颜色的散点图中添加图例而不是颜色条。

我正在寻找像this这样的散点图。我目前的图形如下：

我想知道我是否可以像第二个子图一样在第一个子图中添加一个图例而不是一个颜色条。

创建散点图的功能：

def scatter_it(x): # x=8 für Monate, x=9 für Jahre
    """Punktdiagramm mit farblicher Markierung der Monate bzw. Jahre."""
    plt.figure("Station: {0}, Monat(e): {1}, Jahr(e):{2}".format(Station,months,years))
    plt.style.use('seaborn-whitegrid')

    if x == 8:
        # setting a standard color as first color of cmap rainbow
        farben = plt.cm.get_cmap('rainbow', 13)
        newcolors = farben(np.linspace(0, 1, 13))
        b = np.array([31/256, 19/256, 180/256, 1]) # standard color # blue: 31/119/180 # black: 0/0/0
        newcolors[:1, :] = b
        newcmp = ListedColormap(newcolors)
        cmap = newcmp
    else:
        cmap = 'tab20'

    plt.subplot(2, 1, 1)
    plt.title("Art der Korrelation: Kendalls ${\mathrm{T}}_b$\n" +
              "Korrelation: " + str(r_tp[0]) +
              "\np-Wert (2-seitig): " + str(r_tp[1]) +
              "\nStation: {0}, Monat(e): {1}, Jahr(e):{2}\n".format(Station,months,years),
              loc='left', wrap=True)
    sct = plt.scatter(master_arrayFilter[:,1], # Marsdistanz (in AE)
            master_arrayFilter[:,2], # Temperatur (in °C)
            c=master_arrayFilter[:,x], # Monate bzw. Jahre
            cmap=plt.cm.get_cmap(cmap, np.unique(master_arrayFilter[:,x])[-1]+1-np.unique(master_arrayFilter[:,x])[0]),
            #teilt die colormap rainbow_r od. tab20 in n (=max-min) benötigte Abschnitte auf #leider auch in ggf. nicht benötigte Zwischenschritte
            vmin = master_arrayFilter[np.argmin(master_arrayFilter[:,x], axis=0),x]-.5,
            #vmin gibt unteres Ende der Skala an und setzt die Markierung mittig
            vmax = master_arrayFilter[np.argmax(master_arrayFilter[:,x], axis=0),x]+.5)
            #vmax gibt oberes Ende der Skala an und setzt die Markierung mittig
    plt.xlabel("Marsdistanz in AE\n(1 AE = 149.597.870,7 km)")
    plt.ylabel("Temperatur in °C") #für Niderschlag bzw. Sonnenstunden anpassen.
    #plt.tight_layout()
    clb = plt.colorbar(sct, ticks=np.arange(master_arrayFilter[np.argmin(master_arrayFilter[:,x], axis=0),x]-1,
                    master_arrayFilter[np.argmax(master_arrayFilter[:,x], axis=0),x])+1)
    if x == 8:
        y = "Monat(e)"
    else:
        y = "Jahr(e)"
    clb.ax.set_title(y)

#    z = np.unique(master_arrayFilter[:,x])
#    def make_proxy(zvalue, **kwargs):
#        color = cmap
#        return Line2D([0, 1], [0, 1], color=color, **kwargs)
#    proxies = [make_proxy(item, linewidth=2) for item in z]
#    plt.legend(proxies, [str(int(x)) for x in months],
#        loc='upper right', frameon=True, title=y)

    plt.subplot(2, 1, 2)
    if not months:
        md_plot(master_array[:,0], master_array[:,1]) # Graph
        minmaxmarker(master_array[:,0], master_array[:,1]) # Punkte
    else:
        md_plot3(master_array[:,0], master_array[:,1], master_array[:,8], months) # Graph mit Färbung
        minmaxmarker(master_array[:,0], master_array[:,1]) # Punkte

    md_plot2(master_array[:,0], master_array[:,1], master_array[:,6]) # Graph mit Färbung
    minmaxmarker(master_array[:,0], master_array[:,1]) # Punkte

    plt.show()
    plt.close()
    return None

我禁用了我尝试但失败的东西。

以下是使用过的master_array的摘录：

In [211]: print(master_array)
[[ 1.89301010e+07  1.23451036e+00 -8.10000000e+00 ...  1.00000000e+00
   1.00000000e+00  1.89300000e+03]
 [ 1.89301020e+07  1.24314818e+00 -8.50000000e+00 ...  2.00000000e+00
   1.00000000e+00  1.89300000e+03]
 [ 1.89301030e+07  1.25179997e+00 -9.70000000e+00 ...  3.00000000e+00
   1.00000000e+00  1.89300000e+03]
 ...
 [ 2.01903100e+07  1.84236878e+00  7.90000000e+00 ...  1.00000000e+01
   3.00000000e+00  2.01900000e+03]
 [ 2.01903110e+07  1.85066892e+00  5.50000000e+00 ...  1.10000000e+01
   3.00000000e+00  2.01900000e+03]
 [ 2.01903120e+07  1.85894904e+00  9.40000000e+00 ...  1.20000000e+01
   3.00000000e+00  2.01900000e+03]]

Answer 1

因为你的例子依赖于一些外部变量，所以我创建了另一个例子。在您调用散布标签参数时设置，然后您可以直接调用legend：

import matplotlib.pyplot as plt
import numpy as np

master_array = [np.random.uniform(x-.25, x+.25, 10) for x in range(5)]
colors = [plt.cm.jet(x) for x in np.linspace(0, 1, len(master_array))]
for i, values in enumerate(master_array):
    plt.scatter(values, values, color=colors[i], label="test" +str(i))
plt.legend()
plt.show()

可以看看Python Scatter Plot with Colorbar and Legend Issues