MATLAB Function Reference    

Evaluate piecewise polynomial.



v = ppval(pp,xx) returns the value at the points xx of the piecewise polynomial contained in pp, as constructed by spline or the spline utility mkpp.

v = ppval(xx,pp) returns the same result but can be used with functions like fminbnd, fzero and quad that take a function as an argument.


Compare the results of integrating the function cos

with the results of integrating the piecewise polynomial pp that approximates the cosine function by interpolating the computed values x and y.

int1 provides the integral of the cosine function over the interval [a,b], while int2 provides the integral over the same interval of the piecewise polynomial pp.

See Also

mkpp, spline, unmkpp

  pow2 prefdir