Category Archives: Curve fitting

VBA procedures for the Numerical Analysis of Tabular Functions

Posted on March 12, 2022 by dougaj4

Long time on-line friend Alfred Vachris has recently been converting Fortran code developed through his working career into VBA: I had the opportunity to work at Grumman while going to Graduate School and they gave me a part-time job as … Continue reading →

Posted in Coordinate Geometry, Curve fitting, Excel, Fortran, Maths, Newton, UDFs, VBA | Tagged , , , , , , | 1 Comment

CSpline and Malware

Posted on March 13, 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 August 9, 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 , , , , , , , , , , | 5 Comments

LinEstGap with non-linear functions

Posted on March 14, 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 March 3, 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