Category Archives: Link to Python

More Python rotation functions

Posted on 23/02/2018 by dougaj4

The code described in the previous post includes a Python function that rotates 3D coordinates by an angle defined with two vectors, using Rodrigue’s Rotation.  I have now added this function to the IP2_py spreadsheet, where it is used in the … Continue reading →

Posted in Coordinate Geometry, Drawing, Excel, Link to Python, Maths, Newton, NumPy and SciPy, UDFs, VBA, xlwings | Tagged , , , , , , , , | Leave a comment

Fitting 3D circles to scattered points

Posted on 11/02/2018 by dougaj4

Following a comment at update-to-glob_to_loc3-and-loc_to_glob3-functions, I have modified the Python code at the linked site, so it can be run from Excel, via xlwings.  The spreadsheet described below, and the associated Python code, can be download from: 3DCirc.zip The original … Continue reading →

Posted in Coordinate Geometry, Excel, Link to Python, Maths, Newton, NumPy and SciPy, UDFs, VBA, xlwings | Tagged , , , , , , , | 7 Comments

Excel Uservoice and Python for Excel

Posted on 18/12/2017 by dougaj4

The Excel Uservoice site is a forum for users to post suggestions for improvements to Excel.  A suggestion to add native Python support to Excel, as a replacement to VBA, has had by far the most votes since the start, and … Continue reading →

Posted in Computing - general, Excel, Link to Python, VBA | Tagged , , , , | 1 Comment

Section Properties with MeshPY, including torsion and warping

Posted on 09/12/2017 by dougaj4

I recently discovered robbie van leeuwen’s structural engineering blog, which has an open-source set of Python routines for calculation of section properties, including torsion and warping constants.  The program uses the MeshPY Library for generating the finite element meshes required … Continue reading →

Posted in Beam Bending, Concrete, Excel, Finite Element Analysis, Frame Analysis, Link to Python, Maths, Newton, Numerical integration, NumPy and SciPy, Strand7, UDFs, VBA, xlwings | Tagged , , , , , , , , | 11 Comments

Using Alglib least-squares solvers

Posted on 23/09/2017 by dougaj4

Following the last post on using the Python version of Alglib from Excel, via xlwings, this post looks in more detail at alternatives for fitting a non-linear function to a set of data, using the Levenberg-Marquardt method.  The spreadsheet with … Continue reading →

Posted in AlgLib, Curve fitting, Excel, Link to Python, Maths, Newton, NumPy and SciPy, UDFs, VBA, xlwings | Tagged , , , , , , , , , , | 2 Comments