Tag Archives: UDF

Some string functions

Posted on 15/05/2009 by dougaj4

It was pointed out in a comment to this post at Daily Dose of Excel that VBA has a StrReverse function that will (logically enough) reverse a string.  That’s not awfully useful to me (except maybe for Project Euler), but it … Continue reading →

Posted in Excel, UDFs, VBA | Tagged , , , | 5 Comments

Moving Average Function

Posted on 04/05/2009 by dougaj4

The previous post presented a simple moving average user defined function (UDF).  This has been extended to provide additional functionality: A weighted average may be returned; either a linear weight with a specified step value, or a using any specified weighting … Continue reading →

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

Moving averages and User Defined Array Functions

Posted on 25/04/2009 by dougaj4

I have recently needed to work with moving averages on a large-ish data set (about 10,000 rows x 10 columns), and for reasons that I will describe in the next post, decided that a User Defined Function (UDF) would be … Continue reading →

Posted in Arrays, Excel, UDFs, VBA | Tagged , , , , | 8 Comments

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