Category Archives: Maths

Solving cubic equations – background and timing

Posted on 25/10/2022 by dougaj4

For more information on the polynomial functions, including quartic and higher order solvers, see: Solving Quadratic, Cubic, Quartic and higher order equations; examples Re-reading the Wikipedia article on solving cubic equations, I noticed that the trigonometrical solution for finding 3 real … Continue reading →

Posted in Excel, Link to Python, Maths, Newton, NumPy and SciPy, PyXLL, UDFs, VBA | Tagged , , , , , , , , , | Leave a comment

Installing Python and pyxll from scratch

Posted on 26/09/2022 by dougaj4

Updated 28th September 2022. Matplotlib latest version OK. I recently installed Python and pyxll (plus the required additional libraries) on a new computer, which raised a few problems with incompatible versions, so here is a summary of what worked (as … Continue reading →

Posted in Animation, Arrays, Charts, Coordinate Geometry, Differential Equations, Excel, Finite Element Analysis, Link to Python, Maths, Newton, Numerical integration, NumPy and SciPy, Python Pandas, PyXLL, UDFs | Tagged , , , , , , , , , , , , , , | 2 Comments

VBA procedures for the Numerical Analysis of Tabular Functions

Posted on 12/03/2022 by dougaj4

Long time on-line friend Alfred Vachris has recently been converting Fortran code developed through his working career into VBA: I had the opportunity to work at Grumman while going to Graduate School and they gave me a part-time job as … Continue reading →

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

Display Matplotlib animations in Excel

Posted on 28/02/2022 by dougaj4

The latest version of pyxll (5.4.0) allows animations generated in Matplotlib to be simply copied to Excel. A spreadsheet with the examples shown below, and the associated Python code can be downloaded from: Animations2.zip The screenshot below shows the simple … Continue reading →

Posted in Animation, Drawing, Excel, Link to Python, Maths, Newton, NumPy and SciPy, PyXLL, UDFs | Tagged , , , , , , , | 3 Comments

Rounding to significant figures

Posted on 17/02/2022 by dougaj4

Edited 19th Feb 22, following comment from Larry Schuster Excel does not have a function to round numbers to a specified number of significant numbers, and (rather to my surprise) neither does Python. It is not too hard to write … Continue reading →

Posted in Excel, Link to Python, Maths, NumPy and SciPy, PyXLL, UDFs, VBA | Tagged , , , , , , | 7 Comments