Category Archives: Charts

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 , , , , , , , , | 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: As an example … Continue reading

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

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 , , , | 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 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 , , , , , , , | Leave a comment

Displaying trend line equations on line charts

This post is prompted by a recent comment at Using LINEST for non-linear curve fitting which found that the trend line formula displayed on a chart was totally different from that found using the Linest function. The problem was caused by using a … Continue reading

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Editing Charts with the mouse

When editing chart ranges, to either change the limits of the range, or select a new column, I have been in the habit of either selecting a range and editing the text in the Formula Edit Bar, or right clicking, … Continue reading

Posted in Charts, Excel | Tagged , , | 4 Comments

A mystery curve links to Jupyter

Reviewing some of my less visited links recently, I was intrigued by a post at The Math Less Travelled: The previous post at the site provides more details of the source of the curve, and some links to an interactive … Continue reading

Posted in Charts, Charts, Excel, Maths, Newton | Tagged , , , , , , | 2 Comments