PPoly#
- class scipy.interpolate.PPoly(c, x, extrapolate=None, axis=0)[source]#
- Piecewise polynomial in terms of coefficients and breakpoints - The polynomial between - x[i]and- x[i + 1]is written in the local power basis:- S = sum(c[m, i] * (xp - x[i])**(k-m) for m in range(k+1)) - where - kis the degree of the polynomial.- Parameters:
- cndarray, shape (k, m, …)
- Polynomial coefficients, order k and m intervals. 
- xndarray, shape (m+1,)
- Polynomial breakpoints. Must be sorted in either increasing or decreasing order. 
- extrapolatebool or ‘periodic’, optional
- If bool, determines whether to extrapolate to out-of-bounds points based on first and last intervals, or to return NaNs. If ‘periodic’, periodic extrapolation is used. Default is True. 
- axisint, optional
- Interpolation axis. Default is zero. 
 
 - See also - BPoly
- piecewise polynomials in the Bernstein basis 
 - Notes - High-order polynomials in the power basis can be numerically unstable. Precision problems can start to appear for orders larger than 20-30. - Attributes:
- xndarray
- Breakpoints. 
- cndarray
- Coefficients of the polynomials. They are reshaped to a 3-D array with the last dimension representing the trailing dimensions of the original coefficient array. 
- axisint
- Interpolation axis. 
 
 - Methods - __call__(x[, nu, extrapolate])- Evaluate the piecewise polynomial or its derivative. - derivative([nu])- Construct a new piecewise polynomial representing the derivative. - antiderivative([nu])- Construct a new piecewise polynomial representing the antiderivative. - integrate(a, b[, extrapolate])- Compute a definite integral over a piecewise polynomial. - solve([y, discontinuity, extrapolate])- Find real solutions of the equation - pp(x) == y.- roots([discontinuity, extrapolate])- Find real roots of the piecewise polynomial. - extend(c, x)- Add additional breakpoints and coefficients to the polynomial. - from_spline(tck[, extrapolate])- Construct a piecewise polynomial from a spline - from_bernstein_basis(bp[, extrapolate])- Construct a piecewise polynomial in the power basis from a polynomial in Bernstein basis. - construct_fast(c, x[, extrapolate, axis])- Construct the piecewise polynomial without making checks.