Author Archives: dougaj4

Stepping through Python code called from Excel

Posted on 31/03/2020 by dougaj4

Setting up your editor to allow Python code debugging for functions called from Excel can be tricky, depending on the details of your editor and linking software, but using the Visual Studio Code Editor and Pyxll, this works for me: … Continue reading →

Posted in Computing - general, Excel, Link to Python, PyXLL, UDFs | Tagged , , , , | 4 Comments

More Python Traps

Posted on 30/03/2020 by dougaj4

I recently posted on some Python Traps, focussing on code where changes in the values of sub-routine arguments were not reflected in the calling routines.  The reverse can also be a problem: if an array, a, is passed to a … Continue reading →

Posted in Arrays, Excel, Link to Python, Newton, NumPy and SciPy, PyXLL, UDFs | Tagged , , , , , | Leave a comment

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

Katherine Johnson, NASA Legend

Posted on 26/02/2020 by dougaj4

Cartoon by Steve Breen from The San-Diego Union Tribune. More on Katherine Johnson.

Posted in Maths, Newton | Tagged , , | Leave a comment