.. _docs-meteoinfolab-numeric-fitting-polyval: ********** polyval ********** .. currentmodule:: numeric.fitting .. function:: polyval(p, x) Evaluate a polynomial at specific values. If p is of length N, this function returns the value: p[0]*x**(N-1) + p[1]*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. :param p: (*array_like*) 1D array of polynomial coefficients (including coefficients equal to zero) from highest degree to the constant term. :param x: (*array_like*) A number, an array of numbers, or an instance of poly1d, at which to evaluate p. :returns: Polynomial value Examples:: from mipylib.numeric import fitting x = linspace(0, 4*pi, 10) y = sin(x) #Plot data points plot(x, y, 'ro', fill=False, size=1) #Use polyfit to fit a 7th-degree polynomial to the points r = fitting.polyfit(x, y, 7) #Plot fitting line xx = linspace(0, 4*pi, 100) p = r[0] yy = fitting.polyval(p, xx) plot(xx, yy, '-b') title('Polynomial fitting example') .. image:: ../../../../_static/news/mi_1.4.1_lab_polyfit.png