How to plot multiple functions on the same figure, in Matplotlib?

How can I plot the following 3 functions (i.e. sin, cos and the addition), on the domain t, in the same figure?

from numpy import *
import math
import matplotlib.pyplot as plt
t = linspace(0, 2*math.pi, 400)
a = sin(t)
b = cos(t)
c = a + b

4 Answers

To plot multiple graphs on the same figure you will have to do:

from numpy import *
import math
import matplotlib.pyplot as plt
t = linspace(0, 2*math.pi, 400)
a = sin(t)
b = cos(t)
c = a + b
plt.plot(t, a, 'r') # plotting t, a separately
plt.plot(t, b, 'b') # plotting t, b separately
plt.plot(t, c, 'g') # plotting t, c separately
plt.show()

Perhaps a more pythonic way of doing so.

from numpy import *
import math
import matplotlib.pyplot as plt
t = linspace(0,2*math.pi,400)
a = sin(t)
b = cos(t)
c = a + b
plt.plot(t, a, t, b, t, c)
plt.show()

Just use the function plot as follows

figure()
...
plot(t, a)
plot(t, b)
plot(t, c)

If you want to work with figure, I give an example where you want to plot multiple ROC curves in the same figure:

from matplotlib import pyplot as plt
plt.figure()
for item in range(0, 10, 1): plt.plot(fpr[item], tpr[item])
plt.show()