Category Archives: Excel

LinEstGap with non-linear functions

Posted on 14/03/2020 by dougaj4

The LinEstGap user defined function (UDF) allows the built-in Linest function to be used on data with empty cells or hidden rows, returning results that agree with the chart trend-line function, which automatically ignores blank cells and hidden data.  It … Continue reading →

Posted in Arrays, Curve fitting, Excel, Maths, Newton, UDFs, VBA | Tagged , , , , , , , , , | 4 Comments

DigitGraph Spreadsheet and WebPlot Digitiser

Posted on 03/03/2020 by dougaj4

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 , , , , , | 5 Comments

Microsoft Python Resources

Posted on 24/02/2020 by dougaj4

In addition to the documentation of their software products, Microsoft now have a huge amount of on-line resources of more general content, including: YouTube: Python for Beginners Probably the largest hurdle when learning any new programming language is simply knowing … Continue reading →

Posted in Computing - general, Excel, Link to Python | Tagged , , , | Leave a comment

Asymmetric Catenary Function

Posted on 31/01/2020 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

Using Excel Solver from VBA

Posted on 28/01/2020 by dougaj4

Using the “record macro” icon in Excel to record the solver process, I had a couple of problems: When I tried to run the recorded macro, I got the message “Compile Error – Sub or Function not defined”. When that … Continue reading →

Posted in Excel, VBA | Tagged , , , , | 1 Comment