Author Archives: dougaj4

Non linear regression – 1

Posted on 01/03/2011 by dougaj4

Recent posts have described how to fit linear equations (or equations that can be made linear) to a set of data, using the Excel Linest functions, or User Defined Functions (UDF’s) linking to the ALGLIB library (see Using LINEST for non-linear … Continue reading →

Posted in AlgLib, Concrete, Excel, Maths, Newton | Tagged , , , | 6 Comments

Charts for discussion

Posted on 24/02/2011 by dougaj4

See the comment from Georg Ströhlein under 2D Spline Interpolation with ALGLIB Here are the charts referred to:

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

3 year report

Posted on 23/02/2011 by dougaj4

As in previous years, I have downloaded the statistics for this blog for the previous year, and pasted them into a worksheet.  The link to each post is preserved in the spreadsheet, so it makes a convenient index to what … Continue reading →

Posted in Excel | Tagged | 4 Comments

ALGLIB linear and polynomial fitting functions

Posted on 17/02/2011 by dougaj4

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 , , , , , , | 5 Comments

Two more letters

Posted on 16/02/2011 by dougaj4

I can’t help feeling that I was a little unfair to Douglas Hofstadter in my last post, so as these were hypothetical letters, I will travel back in time, and send two more, enquiring whether a reductionist or a holistic … Continue reading →

Posted in Newton | Tagged , , , , , , | 2 Comments