Functions > Data Analysis > Interpolation and Prediction > Rational Function Interpolation
  
Rational Function Interpolation
rationalint(vx, vy, x)—Returns the interpolated value at x using rational functions, and the expected error.
The rationalint function performs interpolation at a requested point, x, using a rational function approximation (quotient of polynomials) to the data. This type of interpolation is useful for data with sharp discontinuities, which are handled by the poles in the denominator of the rational function.
The rationalint function is based on RATINT (p.112) from the book "Numerical Recipes in C, The Art of Scientific Computing" (Cambridge University Press), Copyright (C) 1987, 1988 Numerical Recipes Software, and is used under license.
Arguments
vx, vy are real vectors of data values of the same length.
x is the value of the independent variable at which you want to evaluate the interpolation curve. For best results, x should be in the range encompassed by the values of vx.