Let’s plot a polynomial and its first and second derivative. We will make three subplots for the sake of clarity:
func = np.poly1d(np.array([1, 2, 3, 4]).astype(float)) x = np.linspace(-10, 10, 30) y = func(x) func1 = func.deriv(m=1) y1 = func1(x) func2 = func.deriv(m=2) y2 = func2(x)
subplot
function. The first parameter of this function is the number of rows, the second parameter is the number of columns, and the third parameter is an index number starting with 1. Alternatively, you can combine the three parameters into a single number such as 311
. The subplots will be organized in 3 rows and 1 column. Give the subplot the title "Polynomial"
. Make a solid red line.plt.subplot(311) plt.plot(x, y, 'r-’) plt.title("Polynomial")
subplot
function. Give the subplot the title "First Derivative"
. Use a line of blue triangles.plt.subplot(312) plt.plot(x, y1, 'b^’) plt.title("First Derivative")
subplot
function. Give the subplot the title "Second Derivative"
. Use a line of green circles.plt.subplot(313) plt.plot(x, y2, 'go’) plt.title("Second Derivative") plt.xlabel('x’) plt.ylabel('y’) plt.show()
The three subplots with polynomial coefficients 1
, 2
, 3
, and 4
:
We plotted a polynomial and its first and second derivative using three different line styles and three subplots in 3 rows and 1 column (see polyplot3.py
):
import numpy as np import matplotlib.pyplot as plt func = np.poly1d(np.array([1, 2, 3, 4]).astype(float)) x = np.linspace(-10, 10, 30) y = func(x) func1 = func.deriv(m=1) y1 = func1(x) func2 = func.deriv(m=2) y2 = func2(x) plt.subplot(311) plt.plot(x, y, 'r-’) plt.title("Polynomial") plt.subplot(312) plt.plot(x, y1, 'b^’) plt.title("First Derivative") plt.subplot(313) plt.plot(x, y2, 'go’) plt.title("Second Derivative") plt.xlabel('x’) plt.ylabel('y’) plt.show()