# Category Archives: Coordinate Geometry

## Spherical Geometry and Vincenty’s Formulae

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

## Section Properties for Rotated Shapes

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

## 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 , , , , | 1 Comment

## 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

## More updates to ArcSpline and IP2

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