The program at the bottom of this message returns the following runtime warning:
python test.py test.py:5: RuntimeWarning: invalid value encountered in divide return np.where(x==0., 1., np.sin(x)/x) The function works correctly returning x = np.array([ 0., 1., 2., 3., 4., 5., 6., 7., 8., 9., 10.]) y = np.array([ 1. , 0.84147098, 0.45464871, 0.04704 , -0.18920062, -0.19178485, -0.04656925, 0.09385523, 0.12366978, 0.04579094, -0.05440211]) The runtime warning suggests that np.where evaluates np.sin(x)/x at all x, including x=0, even though the np.where function returns the correct value of 1. when x is 0. This seems odd to me. Why issue a runtime warning? Nothing is wrong. Moreover, I don't recall numpy issuing such warnings in earlier versions. import numpy as np import matplotlib.pyplot as plt def sinc(x): return np.where(x==0., 1., np.sin(x)/x) x = np.linspace(0., 10., 11) y = sinc(x) plt.plot(x, y) plt.show() _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion