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Category Archives: Charts
DigitGraph Spreadsheet and WebPlot Digitiser
I have posted here previously a spreadsheet that allows XY data to be extracted from images of graphs, maps or other images of objects in a single plane: How to digitise a scanned image. I have updated the instructions for the … Continue reading
Posted in Charts, Charts, Computing - general, Curve fitting, Drawing, Excel, UDFs, VBA
Tagged DigitGraph, digitize scanned image, Excel, UDF, VBA, WebPlot Digitizer
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 Charts, Excel, Mandelbrot Set, VBA
3 Comments
Numerical Integration; Tanh-Sinh Quadrature v. 4.42
Back to Newton and Excel. I recently received a new update to the Tanh-Sinh Quadrature spreadsheet from Graeme Dennes, which may be downloaded from: Tanh_Sinh Quadrature. From the Readme: The Tanh-Sinh quadrature workbook has been enhanced as follows: The Tanh-Sinh … Continue reading
Posted in Charts, Excel, Maths, Newton, Numerical integration, UDFs, VBA
Tagged Double Exponential, Excel, Gauss-Kronrod, numerical integration, Romberg, Tanh-Sinh method, Tanh-Sinh Quadrature, UDF, VBA
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Numerical Integration; Tanh-Sinh Quadrature v. 4.4
Update 27 Nov 2018: Version 4.41 now available from the link below, with minor modifications for compatibility with Excel 2007. I recently received a new version (4.4) of the numerical integration spreadsheet by Graeme Dennes which is now available for … Continue reading
Posted in Charts, Excel, Maths, Newton, Numerical integration, UDFs, VBA
Tagged Double Exponential, Excel, Gauss-Kronrod, numerical integration, Romberg, Tanh-Sinh method, Tanh-Sinh Quadrature, UDF, VBA
9 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
Plotting Charts With Gaps …
“How do you get VB6 to initialize doubles with +infinity, -infinity and NaN”… and various sorts of Not a Number. Back in 2012 (When is an xy chart not an xy chart) I concluded that it was not possible to … Continue reading
Posted in Arrays, Charts, Charts, Excel, UDFs, VBA
Tagged Chart, NaN, plot blank, XY chart with gaps
5 Comments
Using Matplotlib from Excel with xlwings – update
In February 2016 I posted a spreadsheet with examples of linking to the Python Matplotlib library with xlwings. Since then updates to xlwings required some changes to the python code, specifically plot.show has been replaced with pictures.add. The spreadsheet has … Continue reading
Posted in Charts, Charts, Excel, Link to Python, Newton, NumPy and SciPy, VBA
Tagged Excel, MatPlotlib, Python, update, VBA, xlMatPlot, xlwings, xlwScipy
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