matplotlib - plot programatic function without explictly generating all Y points into a ndarray

plotfunction.py

class YRenderer:
    def __init__(self, x, func):
        self.x = x
        self.func = func
    def __len__(self):
        return len(self.x)
    def __getitem__(self, index):
        return self.func(self.x[index])

Usage example

import numpy as np
from matplotlib import pyplot as plt  
import math

# This simple example still requires X points in an ndarray, old-style:
x = np.arange(0, 10, .1)

# but for y data, we can use the class in the snippet above:
# replace math.sin for any function you want.
# Not that a scalar function is used, not one that operates on ndarrays (so, not np.sin)

y = YRenderer(x, math.sin)  
plt(x, y)
plt.plot(x, y)
plt.show()