作业5 画图

numerical_analysis/5/README.md

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+![image-20210117042146956](https://public.veypi.com/img/screenshot/20210117042146.png)
+
+![image-20210117043700038](https://public.veypi.com/img/screenshot/20210117043700.png)
+
+![image-20210117043750115](https://public.veypi.com/img/screenshot/20210117043750.png)

numerical_analysis/5/main.py

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+import math
+import matplotlib.pyplot as plt
+import numpy as np
+from matplotlib.ticker import LinearLocator
+
+
+def f1(x):
+    return 2 * math.sin(x) - x ** 2 / 10
+
+
+def showf1():
+    t = np.linspace(0, 4, 1000)
+    plt.plot(t, [f1(x) for x in t])
+    plt.show()
+
+
+def f2(x, y):
+    return (1 - x) ** 2 + 100 * (y - x ** 2) ** 2
+
+
+def f3(x, y):
+    return (1.5 - x + x * y) ** 2 + (2.25 - x + x * y ** 2) ** 2 + (2.625 - x + x * y ** 3) ** 2
+
+
+def showf2():
+    fig = plt.figure(figsize=plt.figaspect(1.))
+    ax = fig.add_subplot(1, 1, 1, projection='3d')
+    X = np.arange(-1, 1, 0.05)
+    Y = np.arange(-1, 1, 0.05)
+    X, Y = np.meshgrid(X, Y)
+    # R = np.sqrt(X ** 2 + Y ** 2)
+    Z = f2(X, Y)
+    # Z = np.sin(R)
+
+    surf = ax.plot_surface(X, Y, Z, rstride=1, cstride=1,
+                           cmap=plt.cm.YlGnBu_r,
+                           linewidth=0, antialiased=False)
+    fig.colorbar(surf, shrink=0.5, aspect=5)
+    plt.show()
+
+
+def showf3():
+    fig = plt.figure(figsize=plt.figaspect(1.))
+    ax = fig.add_subplot(1, 1, 1, projection='3d')
+    X = np.arange(-5, 5, 0.25)
+    Y = np.arange(-5, 5, 0.25)
+    X, Y = np.meshgrid(X, Y)
+    # R = np.sqrt(X ** 2 + Y ** 2)
+    Z = f3(X, Y)
+    # Z = np.sin(R)
+
+    surf = ax.plot_surface(X, Y, Z, rstride=1, cstride=1,
+                           cmap=plt.cm.YlGnBu_r,
+                           linewidth=0, antialiased=False)
+    fig.colorbar(surf, shrink=0.5, aspect=5)
+    plt.show()
+
+
+if __name__ == '__main__':
+    showf3()