[FIXED] Define and plot constant function in python

Issue

I am trying to plot a constant function in python (this is not what I am actually trying to do but if I solve this it might be a first step).

import matplotlib.pyplot as plt
import numpy as np


def constant_function(x):
    return 2

t1 = np.arange(0.0,1.0,0.1)
plt.plot(t1,constant_function(t1))

However I get the error

ValueError: x and y must have same first dimension, but have shapes (10,) and (1,)

Solution

One option is to vectorize your function:

import matplotlib.pyplot as plt
import numpy as np


@np.vectorize
def constant_function(x):
    return 2


t1 = np.arange(0.0, 1.0, 0.1)
plt.plot(t1, constant_function(t1))
plt.show()

this way constant_function(t1) will return [2 2 2 2 2 2 2 2 2 2] (i.e. [f(x[0]), f(x[1]), f(x[2]), ...]) instead of just 2 and the dimensions will match.

Answered By - hiro protagonist