Category Archives: Maths

Plotting Mandelbrot

Posted on 15/09/2019 by dougaj4

There are many sites discussing the Mandelbrot Set, but not many examples using VBA to plot the set in Excel, so here is my effort: The spreadsheet (including open source VBA code) may be downloaded from: Mandelbrot chart.zip Note that … Continue reading →

Posted in Charts, Charts, Coordinate Geometry, Drawing, Excel, Maths, Newton, VBA | Tagged , , , | 3 Comments

Solving the Lagrangian Point equation for the Moon

Posted on 23/06/2019 by dougaj4

This post was prompted by a recent question at Fitting high order polynomials, asking for Excel methods to solve the equations for the radius of the Moon’s Lagrangian Point 1. All the methods described in this post have been added to … Continue reading →

Posted in Excel, Maths, Newton, UDFs, VBA | Tagged , , , , , , | 4 Comments

Numerical Integration; Tanh-Sinh Quadrature v. 4.42

Posted on 17/03/2019 by dougaj4

Back to Newton and Excel. I recently received a new update to the Tanh-Sinh Quadrature spreadsheet from Graeme Dennes, which may be downloaded from: Tanh_Sinh Quadrature. From the Readme: The Tanh-Sinh quadrature workbook has been enhanced as follows: The Tanh-Sinh … Continue reading →

Posted in Charts, Excel, Maths, Newton, Numerical integration, UDFs, VBA | Tagged , , , , , , , , | 10 Comments

Multiple Integration with Scipy

Posted on 31/01/2019 by dougaj4

Scipy has 3 functions for multiple numerical integration in the scipy.integrate module: dblquad: Compute a double integral. tplquad: Compute a triple integral’ nquad: Integration over multiple variables. I have written six functions to call these functions from Excel, via Pyxll: Each … Continue reading →

Posted in Excel, Link to Python, Maths, Newton, Numerical integration, NumPy and SciPy, PyXLL, UDFs | Tagged , , , , , | 6 Comments

Another (very slow) way of computing pi

Posted on 24/01/2019 by dougaj4

The previous post included 100 Python code one-liners for calculating pi that recalculates in a fraction of a second.  The video below shows an alternative approach that is a little slower: How much slower?  If you had a computer that would … Continue reading →

Posted in Bach, Maths, Newton | Tagged , , | 2 Comments