Excel add-in with eleven powerful worksheet functions for 1, 2 and 3 variable lookup and interpolation (closest-value, linear, piecewise parabolic or hyperbolic, cubic spline) and polynomial curve fitting. Includes online help and example workbooks. Excel add-in with eleven powerful worksheet functions for 1, 2 and 3 variable lookup and interpolation. Interpolation modes include: closest-value, linear, piecewise parabolic or hyperbolic, cubic spline and polynomial up to 20th order. The functions can also handle tables containing missing and invalid data.Includes functions to fit polynomial curves through a set of X-Y data points and return a table of polynomial curve coefficients, as well as, determine the best fit polynomial curve.