Category Archives: Curve fitting

Weighted Least Squares Regression, using Excel, VBA, Alglib and Python

Posted on 05/02/2017 by dougaj4

Least squares linear regression in Excel is easy.  That’s what the Linest and Trend functions do.  That is, they find the coefficients of a straight line (or higher dimension shape) so that the sum of the squares of the distances of … Continue reading →

Posted in AlgLib, Curve fitting, Excel, Link to Python, Maths, Newton, NumPy and SciPy, UDFs, VBA | Tagged , , , , , , | 9 Comments

xlwSciPy 1.09 – update for xlwings 0.10 and Scipy 0.18.1

Posted on 02/10/2016 by dougaj4

The xlwSciPy spreadsheet (last presented here) has been updated for the latest version of xlwings and Scipy. The new spreadsheet can be downloaded from: xlScipy-xlw.zip including full open source code. The spreadsheet requires Python, including xlwings, Numpy, Scipy and Pandas … Continue reading →

Posted in Arrays, Curve fitting, Excel, Link to Python, Maths, NumPy and SciPy, Python Pandas, UDFs, VBA | Tagged , , , , , , , , | 2 Comments

xlwings 0.7.1, dictionaries, and optional arguments

Posted on 08/04/2016 by dougaj4

xlwings 0.7.0 was published at the beginning of March, and introduced direct support for Python dictionaries, which I have used to demonstrate various options for dealing with optional arguments in Excel User Defined Functions (UDFs).  The latest version, 0.7.1, published … Continue reading →

Posted in Curve fitting, Excel, Link to Python, Maths, NumPy and SciPy, UDFs, VBA | Tagged , , , , , , , , | 1 Comment

Using Linest for non-linear curve fitting, examples, hints and warnings

Posted on 28/06/2015 by dougaj4

Since I wrote Using LINEST for non-linear curve fitting in 2011 it has been by far the most popular post on this blog.  This post (in response to a recent question) provides some more detailed guidance on how to apply the function … Continue reading →

Posted in Curve fitting, Excel | Tagged , , , , , , | 3 Comments