Category Archives: Maths

LinEstGap with non-linear functions

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

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

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Asymmetric Catenary Function

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

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 …

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

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

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