Category Archives: Curve fitting

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

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 , , , , , , | Leave a comment

xlwSciPy 1.09 – update for xlwings 0.10 and Scipy 0.18.1

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 , , , , , , , , | Leave a comment

xlwings 0.7.1, dictionaries, and optional arguments

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

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