Tag Archives: Linest

ALGLIB linear and polynomial fitting functions

As promised here: Fitting high order polynomials this post presents details of four Excel User Defined Functions (UDFs) linking with ALGLIB functions for least squares fitting of linear and polynomial functions.  The new functions are: AL_Linest: AL_LinestCW: AL_PolyFit: and AL_PolyFitCW: These functions have been added … Continue reading

Posted in AlgLib, Excel, Maths, Newton, UDFs, VBA | Tagged , , , , , , | 2 Comments

Fitting high order polynomials

This post is a follow up to Using LINEST for non-linear curve fitting and the following comments from Scott Rogers and Lori Miller.  Scott found that he was getting different results from Linest and the xy chart trend line for polynomials of … Continue reading

Posted in AlgLib, Charts, Excel, Maths, Newton, UDFs, VBA | Tagged , , , , , , , , | 31 Comments

Using LINEST for non-linear curve fitting

Update 14 March 2020: See LinEstGap with non-linear functions for the latest version of Linest-Poly with new functions for non-linear curves allowing more convenient input and work with data with gaps errors, and/or hidden lines. Update 28 June 2015:  Also see … Continue reading

Posted in Charts, Excel, Maths, Newton | Tagged , , , , , | 91 Comments

Chart Trend Lines and the Linest Function

At the Mr Excel discussion forum the output of the worksheet function Linest(), compared with chart trend lines raised a question, where it is said that in Excel 2007 the trend line gives different (and incorrect) coefficients for a polynomial curve … Continue reading

Posted in Excel, Maths | Tagged , , , , | 1 Comment