Category Archives: Coordinate Geometry

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

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

Arc-spline update

The input for the first version of the Arcspline function required the coordinates of the centre of each arc, as well as the angle of the tangents at each end of the arc.  I have now added a new version with … Continue reading

Posted in Coordinate Geometry, Excel, Maths, Newton, UDFs, VBA | Tagged , , , , | 7 Comments

Using VBA Evaluate as an Array Function

I recently discovered from a thread at  Chandoo’s Excel Forum that the VBA Evaluate function can be used as an array function.  As a simple example: Range(“A11:A16”).Value = Evaluate(“= B11:B16 + C11:C16”) will add the values in columns B and C, … Continue reading

Posted in Arrays, Coordinate Geometry, Excel, Maths, UDFs, VBA | Tagged , , , , | 2 Comments

Arcs and arc-splines

I have added two user defined functions (UDFs) to the IP2 spreadsheet to generate coordinates for a single  arc, or a series of arcs connected (if necessary) by straight lines.  The new version may be downloaded from: IP2.zip As an example … Continue reading

Posted in Animation, Charts, Charts, Coordinate Geometry, Drawing, Excel, Maths, UDFs, VBA | Tagged , , , , , , | 1 Comment

Using Section Properties- Group

Following a recent comment I have updated the documentation for finding the section properties of groups of shapes in the Section-Properties-Group spreadsheet.  The revised file can be downloaded from: Section Properties07-Group.zip The screenshots below illustrate use of the Group function to … Continue reading

Posted in Coordinate Geometry, Excel, Maths, Newton, Numerical integration, UDFs, VBA | Tagged , , , , , | 7 Comments

IP2_py Update for Python3

The spreadsheet IP2_py provides a large number of geometric functions, including intersection points of lines, circles and planes, interpolation, rotations, and converting between coordinate systems.  Many of the functions are available in VBA and Python versions.  The Python code has now … Continue reading

Posted in Coordinate Geometry, Excel, Link to Python, Maths, Newton, NumPy and SciPy, UDFs, VBA, xlwings | Tagged , , , , , , , , , , | Leave a comment