Category Archives: Coordinate Geometry

Spherical Geometry and Vincenty’s Formulae

Posted on September 27, 2020 by dougaj4

Wikipedia has detailed articles on: Spherical Geometry  and Vincenty’s Formulae (for geometric calculations on an ellipsoid). The spreadsheet Vincenty.zip uses those resources to perform the following calculations, using both on-sheet calculations and VBA user-defined functions (UDF’s): Calculation of distance and … Continue reading →

Posted in Computing - general, Coordinate Geometry, Excel, Maths, Newton, UDFs, VBA | Tagged , , , , , , | 6 Comments

Section Properties for Rotated Shapes

Posted on August 6, 2020 by dougaj4

I have just posted an update to my section properties spreadsheet, last discussed at: Using Section Properties- Group The new version can be downloaded from: Section Properties07-Group.zip The main sheet provides section properties for a wide variety of defined shapes: This … Continue reading →

Posted in Beam Bending, Coordinate Geometry, Excel, Frame Analysis, Maths, Newton, UDFs, VBA | Tagged , , , , | Leave a comment

Asymmetric Catenary Function

Posted on January 31, 2020 by dougaj4

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 , , , , | 1 Comment

Plotting Mandelbrot

Posted on September 15, 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

More updates to ArcSpline and IP2

Posted on December 27, 2018 by dougaj4

I have uploaded version 2.18 of the IP2 spreadsheet to: IP2.zip The new version includes updates to the IP, IP_4, and ArcSpline functions, as described below.  The download is free and includes full open-source code. The IP and IP_4 functions find … Continue reading →

Posted in Arrays, Coordinate Geometry, Excel, Maths, Newton, UDFs, VBA | Tagged , , , , , , , | Leave a comment