Category Archives: Maths

More Python rotation functions

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

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 , , , , , , , | 1 Comment

Evaluating text with units and finding the neutral axis

A few weeks ago a comment asked for guidance on finding the moment capacity of a reinforced concrete section.  This post will look at finding the depth of the neutral axis (NA) in a rectangular section, with a single layer of … Continue reading

Posted in Beam Bending, Concrete, Excel, Maths, Newton, UDFs, VBA | Tagged , , , , , , , , , , | 2 Comments

Section Properties with MeshPY, including torsion and warping

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 , , , , , , , , | 4 Comments

Brent’s Method; Update and Examples

Has the free software at this site saved you time and/or money? If so, please contribute to the Raw Impact charity group providing practical help to poor communities in Cambodia: Everydayhero – Cambodia 2018 All contributions gratefully accepted. Contributions are … Continue reading

Posted in Arrays, Excel, Maths, Newton, UDFs, VBA | Tagged , , , , , , | Leave a comment

Update to AL-Spline-Matrix

Has the free software at this site saved you time and/or money? If so, please contribute to the Raw Impact charity group providing practical help to poor communities in Cambodia:  Everydayhero – Cambodia 2018 All contributions gratefully accepted. Contributions are … Continue reading

Posted in AlgLib, Excel, Maths, Newton, UDFs, VBA | Tagged , , , , , , | 1 Comment

Hofstadter, Pahud, Bach

The latest ACO concert series features the Swiss flautist Emmanuel Pahud (interview here). The performance included J.S. Bach’s 6 Part Ricercar, from The Musical Offering, which was the inspiration for the final dialogue in Douglas Hofstadter’s Godel, Esher, Bach: Achilles … Continue reading

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