Category Archives: Maths

LinEstGap with non-linear functions

Posted on March 14, 2020 by

The LinEstGap user defined function (UDF) allows the built-in Linest function to be used on data with empty cells or hidden rows, returning results that agree with the chart trend-line function, which automatically ignores blank cells and hidden data.  It … Continue reading →

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

Katherine Johnson, NASA Legend

Posted on February 26, 2020 by

Cartoon by Steve Breen from The San-Diego Union Tribune. More on Katherine Johnson.

Posted in Maths, Newton | Tagged , , | Leave a comment

Asymmetric Catenary Function

Posted on January 31, 2020 by

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 , , , , | Leave a comment

More powers of 3

Posted on October 20, 2019 by

Following the discovery of a question to which the answer is 42, the same team has now reported a sum of three cubes equal to 3.  As before, the result can be checked from Excel, linking to mpmath, via pyxll. … Continue reading →

Posted in Computing - general, Excel, Link to Python, Maths, Newton, PyXLL | Tagged , , , , , | Leave a comment

The answer to Life the Universe and Everything …

Posted on September 19, 2019 by

is 42, as is well-known: The actual question, to which the answer is 42, is not known, but a lesser known long standing question involving this number has recently been solved: The original problem, set in 1954 at the University … Continue reading →

Posted in Computing - general, Excel, Maths, Newton, PyXLL | Tagged , , , , | 5 Comments

Plotting Mandelbrot

Posted on September 15, 2019 by

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 June 23, 2019 by

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 , , , , , , | 3 Comments