Category Archives: Newton

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

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

Paul Kelly and Joni Mitchell

Posted on 08/02/2020 by dougaj4

Leading Australian singer-songwriter Paul Kelly is about to release a powerful new single that tackles Australia’s lack of action on climate change and environmental destruction. Entitled Sleep, Australia, Sleep, Kelly says the song is both “a lament in the form … Continue reading →

Posted in Bach, Climate | 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