polyval(p, x, *, unroll=16)¶
Evaluate a polynomial at specific values.
LAX-backend implementation of
unrollparameter is JAX specific. It does not effect correctness but can have a major impact on performance for evaluating high-order polynomials. The parameter controls the number of unrolled steps with
polyvalimplementation. Consider setting
unroll=128(or even higher) to improve runtime performance on accelerators, at the cost of increased compilation time.
Original docstring below.
If p is of length N, this function returns the value:
p*x**(N-1) + p*x**(N-2) + ... + p[N-2]*x + p[N-1]
If x is a sequence, then p(x) is returned for each element of x. If x is another polynomial then the composite polynomial p(x(t)) is returned.
p (array_like or poly1d object) – 1D array of polynomial coefficients (including coefficients equal to zero) from highest degree to the constant term, or an instance of poly1d.
x (array_like or poly1d object) – A number, an array of numbers, or an instance of poly1d, at which to evaluate p.
values – If x is a poly1d instance, the result is the composition of the two polynomials, i.e., x is “substituted” in p and the simplified result is returned. In addition, the type of x - array_like or poly1d - governs the type of the output: x array_like => values array_like, x a poly1d object => values is also.
- Return type
ndarray or poly1d
I. N. Bronshtein, K. A. Semendyayev, and K. A. Hirsch (Eng. trans. Ed.), Handbook of Mathematics, New York, Van Nostrand Reinhold Co., 1985, pg. 720.