You are not logged in.
login | register
Tool: CurvFit
Screenshot:
Tool Thumbnail

Go to: http://fortrancalculus.info/apps/curvfit.html (opens a new window)
Description:

CurvFit (tm) is a nonlinear curve fitting program. Sine, damped Sine, Lorentz, Modified Lorentz, Power (ie Polynomial) and Exponential series are presently available models to match your data. We strongly suggest trying a Lorentz series for data with multiple peaks or valleys. A calculator exists for interpolation &/or extrapolation of given data. CurvFit has proven excellent for hard to fit data. Hard to fit data may take more time -but- it can be done given the right series and parameter values. For start try curve fitting your data with a Lorentz series!

A Lorentz function equals 1 / (1 + a x2). This is a shortened form of the infinite series inverse (1 + Σ ai x2i). For practical purposes the shortened Lorentz function is accurate enough. The Lorentz function equals the derivative of the arctangent.

A Modified Lorentz function equals (1 + x) / (1 + a x2) = (1 + x) * Lorentz function! Use the modified Lorentz when minimizing number of terms in your curve fit series. (Someone suggested that the modified Lorentz is a Bessel function, is it?)

Fitting Sinusoidal data is possible too.

Technology Type: Computer 
Author: Optimal Designs Enterprise
Language: English 
Cost: Does not require payment for use

Average Rating:  [0] Login to rate this resource
My MathTools: Login to Subscribe / Save This
Reviews: be the first to review this resource
Discussions: start a discussion of this resource

Courses: Algebra Quadratic Systems, Exponential Functions
Algebra II Exponential Functions, Sequences and Series
Trigonometry Trig Functions, Series
PreCalculus Functions, Sequences and Series
Calculus Functions, Graphs, and Limits