To illustrate how plotting works, let’s display some polynomial graphs. We will use the NumPy polynomial function poly1d
to create a polynomial.
poly1d
function to create a polynomial.func = np.poly1d(np.array([1, 2, 3, 4]).astype(float))
x
values with the NumPy linspace
function. Use the range -10
to 10
and create 30
even spaced values.x = np.linspace(-10, 10, 30)
y = func(x)
plot
function; this does not immediately display the graph.plt.plot(x, y)
xlabel
function.plt.xlabel('x’)
ylabel
function.plt.ylabel('y(x)’)
show
function to display the graph.plt.show()
Here is a plot with polynomial coefficients 1
, 2
, 3
, and 4
:
We displayed a graph of a polynomial on our screen. We added labels to the x
and y
axis (see polyplot.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) plt.plot(x, y) plt.xlabel('x’) plt.ylabel('y(x)’) plt.show()