2、线性分段彩色图
import numpy as np
import matplotlib.pyplot as plt
from matplotlib import cm
from matplotlib.colors import LinearSegmentedColormap
plt.rcParams['font.sans-serif'] = ['SimHei']
plt.rcParams['axes.unicode_minus'] = False
viridis = cm.get_cmap('viridis', 8)
def plot_examples(colormaps):
"""
Helper function to plot data with associated colormap.
"""
np.random.seed(20220225)
data = np.random.randn(30, 30)
n = len(colormaps)
fig, axs = plt.subplots(1, n, figsize=(n * 2 + 2, 3),
constrained_layout=True, squeeze=False)
for [ax, cmap] in zip(axs.flat, colormaps):
psm = ax.pcolormesh(data, cmap=cmap, rasterized=True, vmin=-4, vmax=4)
fig.colorbar(psm, ax=ax)
plt.title("线性分段彩色图",x=0)
plt.show()
colors = ["darkorange", "gold", "lawngreen", "lightseagreen"]
cmap1 = LinearSegmentedColormap.from_list("mycmap", colors)
nodes = [0.0, 0.4, 0.8, 1.0]
cmap2 = LinearSegmentedColormap.from_list("mycmap", list(zip(nodes, colors)))
plot_examples([cmap1, cmap2])
