Category Archives: UDFs

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

Debugging with xlwings and PyCharm

Posted on 26/01/2017 by dougaj4

The xlwings documentation covers de-bugging, but it is very brief and it took me some time to get everything working, so this article covers the process in a bit more detail.  The details are affected by the editor being used, … Continue reading →

Posted in Excel, Link to Python, UDFs, VBA | Tagged , , , , , , | Leave a comment

3D Frame analyses with spring releases – 2

Posted on 04/01/2017 by dougaj4

The latest version of the 3DFrame spreadsheet (previously presented here) includes provision for spring end releases, allowing for either rotational or translational springs in any direction.  These springs are now incorporated in the model by adjustment of the beam properties, … Continue reading →

Posted in Beam Bending, Excel, Finite Element Analysis, Frame Analysis, Newton, Strand7, UDFs, VBA | Tagged , , , , , | Leave a comment

Brent’s Method and a daft engineer’s blog

Posted on 23/12/2016 by dougaj4

Browsing links on Brent’s Method I found: Daft Engineer – Numerical Methods and Excel* which is well worth a look (plenty of stuff on statistics and Python, with the odd dash of Excel).  The link has VBA code for a … Continue reading →

Posted in Excel, Maths, Newton, UDFs, VBA | Tagged , , | 3 Comments

3D Frames, axes and stiffness matrices

Posted on 09/12/2016 by dougaj4

In the course of adding provision for spring end releases to the 3DFrame spreadsheet, I have also tidied up the code for generating the structure stiffness matrix, and added some documentation to the spreadsheet.  The revised spreadsheet (version 2.02) can … Continue reading →

Posted in Arrays, Beam Bending, Excel, Finite Element Analysis, Frame Analysis, Newton, Strand7, UDFs, VBA | Tagged , , , , , , , , | 10 Comments