Category Archives: Newton

Plotting Freeze-Thaw Data …

… or other irregular cyclic data. Another Eng-Tips question asked how to approximate ice area over a freeze-thaw cycle using a function based on a sine or cosine curve.  The screen-shot below shows three alternatives: Using built in Excel functions requires … Continue reading

Posted in Arrays, Curve fitting, Excel, Maths, Newton, UDFs, VBA | Tagged , , , , , | 1 Comment

Counting non-pecked chicks

Download file:  Binary Chicks.zip. This post is based on a recent discussion at Cosmic Horizons looking at numerical methods to solve the following problem: The answer to the question is straightforward: With a little thought, you should be able to realise … Continue reading

Posted in Excel, Link to Python, Maths, Newton, UDFs, VBA, xlwings | Tagged , , , , , , , | Leave a comment

3DFrame update

The update to the Glob_to_loc3 and Loc_to_glob3 functions (and associated functions) has now been transferred to the 3DFrame spreadsheet, which will now give correct results when beams are defined in the global negative Z direction.  The revised spreadsheet (including full … Continue reading

Posted in Beam Bending, Excel, Finite Element Analysis, Frame Analysis, Newton, Strand7, VBA | Tagged , , , , , | Leave a comment

Update to Glob_to_loc3 and Loc_to_glob3 functions

Following a comment here I have updated the Glob_to_loc3 and Loc_to_glob3 functions to deal with some problems when the local longitudinal axis is parallel to the global Y or Z axes.  The IP2 spreadsheet, including the revised functions, can be downloaded from: … Continue reading

Posted in Coordinate Geometry, Excel, Finite Element Analysis, Frame Analysis, Newton, UDFs, VBA | Tagged , , , , , , | Leave a comment

Using Matplotlib from Excel with xlwings – update

In February 2016 I posted a spreadsheet with examples of linking to the Python Matplotlib library with xlwings.  Since then updates to xlwings required some changes to the python code, specifically plot.show has been replaced with pictures.add. The spreadsheet has … Continue reading

Posted in Charts, Charts, Excel, Link to Python, Newton, NumPy and SciPy, VBA | Tagged , , , , , , , | Leave a comment

More on trend line equations on line charts

In the previous post we saw that if a trend line equation is added to a line chart it will return the wrong coefficients if the x values are not a continuous sequence of integers, starting at 1 (click on … Continue reading

Posted in Charts, Excel, Maths, Newton | Tagged , , , , | 1 Comment

Displaying trend line equations on line charts

This post is prompted by a recent comment at Using LINEST for non-linear curve fitting which found that the trend line formula displayed on a chart was totally different from that found using the Linest function. The problem was caused by using a … Continue reading

Posted in Charts, Charts, Excel, Maths | Tagged , , , | Leave a comment