Category Archives: UDFs

Extracting numbers with regular expressions

Posted on 12/04/2014 by dougaj4

Shortly after I wrote about extracting numbers from text strings, Winston Snyder at dataprose.org wrote a detailed article about using “regular expressions” to separate text from numbers in any string.  I have adapted his routine for the same purpose as … Continue reading →

Posted in Excel, UDFs, VBA | Tagged , , , , | 19 Comments

Dynamic sorting with Excel, VBA, and Python

Posted on 31/03/2014 by dougaj4

A spreadsheet with User Defined Functions (UDFs) to dynamically sort a range of data has previously been presented here and here. I have now modified the Python version of the UDF for improved functionality, added a second Python function, and … Continue reading →

Posted in Excel, Link to Python, NumPy and SciPy, UDFs, VBA | Tagged , , , , , | 1 Comment

Global to Local for plates (and three node beams)

Posted on 02/03/2014 by dougaj4

The Glob_to_Loc function (see Converting from global to local coordinates (and vice versa) ) converts forces and deflections of a beam from the global coordinate system to the local system, defined by the longitudinal axis of the beam and a rotation angle … Continue reading →

Posted in Coordinate Geometry, Excel, Finite Element Analysis, Frame Analysis, Link to Python, Maths, Newton, Strand7, UDFs, VBA | Tagged , , , , , , , | 3 Comments

Rabbits, Foxes, and Lorenz Attractors

Posted on 23/02/2014 by dougaj4

Following comments here and here I have added two examples to the ODE Solver spreadsheet showing use of the ODE function to solve systems of differential equations with two or more coupled equations. The new version (including full open source … Continue reading →

Posted in AlgLib, Differential Equations, Excel, Maths, Newton, UDFs, VBA | Tagged , , , , , , , , | 2 Comments

Cubic splines with horizontal data

Posted on 16/02/2014 by dougaj4

Following a request here I have modified my cubic spline functions to accept input arranged  in rows as well as columns.  By default the output arrays will have the same orientation as the range of interpolation X values, but I have also added … Continue reading →

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