Category Archives: UDFs

Excel to Alglib via xlwings

The Alglib library provides many valuable numerical analysis routines, but the VBA version is no longer actively maintained.  The latest versions are available in C++, C#, and Python, of which the Python version (in conjunction with xlwings) provides the easiest interface … Continue reading

Posted in AlgLib, Curve fitting, Excel, Link to Python, Maths, Newton, Numerical integration, UDFs, VBA, xlwings | Tagged , , , , , , , , , | 1 Comment

Stress increments in prestressed concrete beams

The two main Australian Standards covering prestressed concrete structures (AS 3600, Concrete Structures, and AS 5100 Part 5, Concrete Bridges) put a limit on the allowable increase in stress in reinforcement and prestressing strands and tendons, when the load increases from … Continue reading

Posted in Beam Bending, Concrete, Excel, Newton, UDFs, VBA | Tagged , , , , , , | 1 Comment

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 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

Taming Symbols in Excel

You can enter an ASCII character in Excel (if you know the ASCII code) by holding  down the Alt key and entering the decimal code value on the numeric key pad.  This has two problems: It doesn’t work in Excel … Continue reading

Posted in Excel, UDFs, VBA | Tagged , , , , , , | 1 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

Working with milliseconds in Excel

A recent post at Eng-Tips looked for a solution to problems with working with times in Excel, when time differences are required to the nearest millisecond. The problem is that although times may be entered as a time/date value, and formatted … Continue reading

Posted in Computing - general, Excel, UDFs, VBA | Tagged , , , , , , | 1 Comment