Category Archives: Curve fitting

CSpline and Malware

Posted on 13/03/2021 by dougaj4

I was recently informed that the Malwarebyte program was raising a warning for the CSpline2 download. On checking I found that the spreadsheet had a VBA module called frmPickwb which was not my code. The file has now been updated, … Continue reading →

Posted in Computing - general, Curve fitting, UDFs, VBA | Tagged , , | Leave a comment

Deflections and Moments in Rectangular Plates

Posted on 09/08/2020 by dougaj4

Following a question here I have compared tabulated coefficients for deflections and bending moments in a rectangular plate with results of a Strand7 analysis using 8 noded plate/shell elements.  The results are summarised below, and in a spreadsheet which also … Continue reading →

Posted in Beam Bending, Curve fitting, Excel, Finite Element Analysis, Newton | Tagged , , , , , , , , , , | 7 Comments

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

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