Category Archives: Maths

Floating Point Precision Problems

Posted on 05/04/2021 by dougaj4

A question on Quora : prompted me to look at how these numbers are handled in Excel, in VBA called from Excel, and in Python called from Excel via pyxll. The results are shown in the screenshot below: Column A … Continue reading →

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

Eval and Let examples

Posted on 21/02/2021 by dougaj4

Final example updated 28th Feb 2021, following comment from Craig: There are many examples of the use of the new Let function on the web (see my previous post on this topic for links). This post compares use of Let … Continue reading →

Posted in Excel, Maths, UDFs, VBA | Tagged , , , , , | 9 Comments

Units4Excel Update

Posted on 29/12/2020 by dougaj4

As discussed here, I have updated the Units4Excel spreadsheet, with the list of non-SI units updated from the latest Wikipedia table. The EvalU user defined function (UDF) has also been modified with three output options, as shown in the screen-shot … Continue reading →

Posted in Excel, Maths, Newton, UDFs, VBA | Tagged , , , , | 5 Comments

Tanh-Sinh Quadrature update

Posted on 26/11/2020 by dougaj4

Following some comments here Graeme Dennes and I have modified the start-up code for the Tanh-Sinh Quadrature spreadsheet to avoid problems opening the file when first downloaded, or copied to a new computer. The new file is located (as before) … Continue reading →

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

Newton-Raphson and Brent’s Method – Solver examples

Posted on 08/11/2020 by dougaj4

I recently discovered the Computing Skillset site (via open-struct-engineer), which has good information on the basis and use of the Newton-Raphson method: The Newton Raphson method explained, details, pictures, python code Highly instructive examples for the Newton Raphson method I … Continue reading →

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