Category Archives: UDFs

Asymmetric Catenary Function

Posted on 31/01/2020 by dougaj4

Back in 2009, I posted a user defined function (UDF) to generate a catenary curve, that could be used together with the Excel Solver to generate a curve of a specified span and sag: A catenary function Following a discussion … Continue reading →

Posted in Coordinate Geometry, Curve fitting, Excel, Maths, Newton, UDFs, xlwings | Tagged , , , , | 1 Comment

Column buckling under multiple loads

Posted on 20/01/2020 by dougaj4

Following another buckling discussion at Eng-tips I have modified my Frame4-buckle spreadsheet to allow input of multiple axial loads at any point along the column, along with any number of sections with different section properties.  Background on the method used … Continue reading →

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

Python Traps

Posted on 01/01/2020 by dougaj4

When converting existing VBA code to Python there are a number of obvious changes to the syntax that need to be made for the code to run at all, but there are also a number of not so obvious traps … Continue reading →

Posted in Arrays, Excel, Link to Python, Newton, NumPy and SciPy, PyXLL, UDFs, VBA | Tagged , , , , , , , , | 1 Comment

Excel Dynamic Arrays

Posted on 08/12/2019 by dougaj4

Previews of dynamic arrays in Excel have been available for some time through the “Insider” programme.  They are now being published to general subscribers through Office 365 monthly updates: Further information is given at: Easier array formulas and Dynamic array … Continue reading →

Posted in Arrays, Excel, UDFs | Tagged , , , , , | Leave a comment

A problem with integers in VBA

Posted on 01/10/2019 by dougaj4

A recent question at Quora asked: “Why am I getting an overflow error in Excel VBA when doing a simple arithmetic calculation like str1 = 24*60*30 where str1 is a variant or long or double?” I hadn’t encountered that problem … Continue reading →

Posted in Excel, UDFs, VBA | Tagged , , , | Leave a comment