Category Archives: Maths

Computing and plotting the Mandelbrot set in Excel …

Posted on 07/12/2021 by dougaj4

… with Python, Numba and pyxll. As promised in the previous post, this post will look at alternative procedures for calculating and plotting the Mandelbrot set with Python based code. The spreadsheet presented here and the associated Python code may … Continue reading →

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

Animations from VBA

Posted on 28/11/2021 by dougaj4

A convenient way to create an animation in Excel is to create on-sheet formulas or user defined functions to generate the required data, then use VBA to iterate through the range of input values so that the chart or image … Continue reading →

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

Tanh-Sinh Quadrature v. 5.03

Posted on 22/11/2021 by dougaj4

Following some recent comments Graeme Dennes has released the latest version the Tanh-Sinh Quadrature spreadsheet with some corrections to the test function documentation. The new file is located (as before) at: Tanh-Sinh Quadrature For more information on the last major release … Continue reading →

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

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