Category Archives: UDFs

More on Worksheetfunction vs UDF

Posted on 22/04/2009 by dougaj4

A recent post at Roy Maclean’s VBA Blog suggested that the difference between using a worksheetfunction call in VBA and writing a User Defined Function (UDF) to do the same job was not enough to be worth worrying about.  He tested … Continue reading →

Posted in Arrays, Excel, UDFs, VBA | Leave a comment

Evaluating Pi …

Posted on 12/04/2009 by dougaj4

… to 15 decimal places in one easy step (or not too difficult step). In my previous post one of the examples given of the use of the Gaussian Quadrature function was to evaluate the value of Pi.  Let’s look at … Continue reading →

Posted in Excel, Maths, Newton, UDFs, VBA | Tagged , , , , | 4 Comments

Gaussian Quadrature

Posted on 10/04/2009 by dougaj4

The previous post on integration provided an Excel User Defined Function (UDF) to perform numerical integration using Simpson’s Rule or the Trapezoidal Rule.  A third method is Gaussian Quadrature which is often much more accurate and/or quicker than Simpson’s Rule.  The UDF GaussInt() … Continue reading →

Posted in Excel, Maths, Newton, UDFs, VBA | Tagged , , , , , , | 27 Comments

Another update to IP.xls

Posted on 07/04/2009 by dougaj4

Following some suggestions from Mike Seymour I have modified my polyline intersection function, and added a new version. The changes are: The data ranges for the new function, IP4(), are entered as four separate ranges, so the X and Y … Continue reading →

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

A Sort Function

Posted on 23/03/2009 by dougaj4

There is often a need to sort data within a VBA routine, but VBA does not have a built in sort function, so I recently had a look for what is on offer on the Internet. Chip Pearson has an … Continue reading →

Posted in Arrays, Excel, UDFs, VBA | Tagged , , , | 21 Comments