Recent Comments
DonB on Biaxial bending update 
Mohd Yousef on Biaxial bending update 
dougaj4 on Beam Fixed End Actions by Maca… 
Peka Odendaal (@PKOd… on Beam Fixed End Actions by Maca… 
Gerardo Freyre on The history of the theory of b… dougaj4 on Time in hours and minutes betw… 
SDAmy on Time in hours and minutes betw… Concrete Stress Bloc… on Equivalent Stress Blocks Concrete Stress Bloc… on Stress blocks in AS 3600 Section Properties f… on Using Section Properties-… dougaj4 on ULS Design Functions and … dougaj4 on ULS Design Functions and … dougaj4 on Using LinEst() on data with… 
Eduardo Torres on Using LinEst() on data with… DonB on ULS Design Functions and …
Category Archives: Curve fitting
Deflections and Moments in Rectangular Plates
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 Excel, FEA, Linest, Moody, Pilkey, plate bending, plate deflections, Plate stresses, Roark, Strand7, Timoshenko
Leave a comment
LinEstGap with non-linear functions
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 Excel, Exponential curves, Linest, Linest with gaps, Log curves, non-linear curve fitting, Polynomial curves, Power curves, UDF, VBA
1 Comment
DigitGraph Spreadsheet and WebPlot Digitiser
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 DigitGraph, digitize scanned image, Excel, UDF, VBA, WebPlot Digitizer
5 Comments
Asymmetric Catenary Function
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 Catenary, Excel, Solver, UDF, VBA
Leave a comment
More circle fitting options with Scipy
A comment on the first post on this topic found that the method used did not work well for short arcs of large radius circles. An example of the problem can be seen in the screen shots below: The function … Continue reading
Posted in Coordinate Geometry, Curve fitting, Excel, Link to Python, Maths, Newton, NumPy and SciPy, UDFs, VBA, xlwings
Tagged curve fitting, Excel, least squares, Numpy, ODR, Python, SciPy, VBA
Leave a comment
