Tag Archives: VBA

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

Evaluate integrals to a specified tolerance

Posted on 10/03/2009 by dougaj4

A previous post presented a user defined function (UDF) to perform a numerical integration of a function specified as a text string.  The UDF allowed the number of subdivisions of the integration range to be specified, but the number of subdivisions required to … Continue reading →

Posted in Excel, Maths, Newton, UDFs | Tagged , , , , , | 2 Comments

Splitters!

Posted on 07/03/2009 by dougaj4

A recent post on the Tek-Tips VBA forum reminded me that VBA has a split function, which will split a string into sub-strings at any specified character (such as a space).  D’oh I thought, why did I waste my time writing … Continue reading →

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