代码之家 › 专栏 › 技术社区 › JKGalbraith

使用Matplotlib基于阵列将颜色渲染为箭头

matplotlib numpy python

JKGalbraith · 技术社区 · 3 年前

V ? 根据预期输出分配值。

import numpy as np
import matplotlib as mpl
import matplotlib.pyplot as plt
from matplotlib.colors import Normalize
import matplotlib.colors as colors
from matplotlib import cm


V=np.array([[10],[20],[30],[40],[50],[60]])

cmap = plt.cm.jet
cNorm  = colors.Normalize(vmin=np.min(V), vmax=np.max(V))
scalarMap = cm.ScalarMappable(norm=cNorm,cmap=cmap)


fig = plt.figure()
ax  = fig.add_axes([0.1, 0.1, 0.7, 0.855]) # [left, bottom, width, height]
axc = fig.add_axes([0.85, 0.10, 0.05, 0.85])

        
for idx in range(0,len(V)):
        colorVal = scalarMap.to_rgba(V[idx])
        ax.arrow(200, 400, -50, -50,width=5, head_length=20, fc='k',ec='k')
        ax.arrow(200, 400, 50, -50, width=5, head_length=20, fc='k', ec='k')
        ax.arrow(200, 400, 0, -50, width=5, head_length=20, fc='k', ec='k')
        ax.arrow(200, 300, 50, 0, width=5, head_length=20, fc='k', ec='k')
        ax.arrow(200, 300, 50, -50, width=5, head_length=20, fc='k', ec='k')
        ax.arrow(400, 300, -50, -50, width=5, head_length=20, fc='k', ec='k')  
        cb1 = mpl.colorbar.ColorbarBase(axc, cmap=cmap,
                                            norm=cNorm,orientation='vertical')
        
ax.set_xlim(left = 0, right = 500)
ax.set_ylim(bottom = 0, top = 500)
plt.show()

预期输出为

1 回复 | 直到 3 年前

r-beginners 3 年前

由于RGBA值是在循环过程中获得的,因此它准备了一个空列表并获得每个箭头的颜色。从获取的列表中,指定结果列表中的颜色。

import numpy as np
import matplotlib as mpl
import matplotlib.pyplot as plt
from matplotlib.colors import Normalize
import matplotlib.colors as colors
from matplotlib import cm

V=np.array([[10],[20],[30],[40],[50],[60]])

cmap = plt.cm.jet
cNorm  = colors.Normalize(vmin=np.min(V), vmax=np.max(V))
scalarMap = cm.ScalarMappable(norm=cNorm,cmap=cmap)


fig = plt.figure()
ax  = fig.add_axes([0.1, 0.1, 0.7, 0.855]) # [left, bottom, width, height]
axc = fig.add_axes([0.85, 0.10, 0.05, 0.85])

color_list = []        
for idx in range(0,len(V)):
        colorVal = scalarMap.to_rgba(V[idx])
        r,g,b,a = colorVal[0].tolist()
        color_list.append((r,g,b,a))
        
ax.arrow(200, 400, -50, -50,width=5, head_length=20, fc=color_list[0],ec=color_list[0])
ax.arrow(200, 400, 50, -50, width=5, head_length=20, fc=color_list[1], ec=color_list[1])
ax.arrow(200, 400, 0, -50, width=5, head_length=20, fc=color_list[2], ec=color_list[2])
ax.arrow(200, 300, 50, 0, width=5, head_length=20, fc=color_list[3], ec=color_list[3])
ax.arrow(200, 300, 50, -50, width=5, head_length=20, fc=color_list[4], ec=color_list[4])
ax.arrow(400, 300, -50, -50, width=5, head_length=20, fc=color_list[5], ec=color_list[5])  
cb1 = mpl.colorbar.ColorbarBase(axc, cmap=cmap,
                                    norm=cNorm,orientation='vertical')
        
ax.set_xlim(left = 0, right = 500)
ax.set_ylim(bottom = 0, top = 500)
plt.show()