Category Archives: UDFs

New sort functions and sorting to groups

I first posted a user defined function (UDF) to sort spreadsheet or VBA data back in 2009.  Finally Microsoft have caught up, and Excel 365 subscribers now have two built in sort functions available: =SORT(array,[sort_index],[sort_order],[by_col]) =SORTBY(array, by_array1, [sort_order1], [by_array2, sort_order2],…) … Continue reading

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Getting near matches from a list with Python

To return a list of near matches from a long list of strings would be quite difficult in VBA (unless I’m missing something), but in Python it is very simple.  Here is the code for this operation, using pyxll to … Continue reading

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Stepping through Python code called from Excel

Setting up your editor to allow Python code debugging for functions called from Excel can be tricky, depending on the details of your editor and linking software, but using the Visual Studio Code Editor and Pyxll, this works for me: … Continue reading

Posted in Computing - general, Excel, Link to Python, PyXLL, UDFs | Tagged , , , , | 4 Comments

More Python Traps

I recently posted on some Python Traps, focussing on code where changes in the values of sub-routine arguments were not reflected in the calling routines.  The reverse can also be a problem: if an array, a, is passed to a … Continue reading

Posted in Arrays, Excel, Link to Python, Newton, NumPy and SciPy, PyXLL, UDFs | Tagged , , , , , | 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 , , , , , , , , , | 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 , , , , , | 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 , , , , | Leave a comment