[Numpy-discussion] Inverse function of numpy.polyval()

Yuxiang Wang yw5aj at virginia.edu
Mon May 19 21:23:12 EDT 2014

Dear all,

I was wondering is there a convenient inverse function of
np.polyval(), where I give the y value and it solves for x?

I know one way I could do this is:

import numpy as np

# Set up the question
p = np.array([1, 1, -10])
y = 100

# Solve
p_temp = p
p_temp[-1] -= y
x = np.roots(p_temp)

However my guess is most would agree on that this code has low
readability. Any suggestions?



Yuxiang "Shawn" Wang
Gerling Research Lab
University of Virginia
yw5aj at virginia.edu
+1 (434) 284-0836

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