Category Archives: UDFs

Solving simultaneous equations – Fortran dll

Posted on 20/12/2008 by dougaj4

The file simultaneous.zip has been modified to allow access to a Fortran simultaneous equation routine, compiled as a dll.  The original file was posted in solving simultaneous equations.  The advantages of a compiled routine include: Much better performance Greater precision through … Continue reading →

Posted in Arrays, Fortran, Link to dll, Maths, UDFs, VBA | Tagged , , , , , | 3 Comments

Trigonometric Functions – dll

Posted on 11/12/2008 by dougaj4

I have converted the trigonometric functions presented in this earlier post into a Fortran dll.  The dll and associated spreadsheet and add-in files can be downloaded from here. This file and the associated file Trig.dll provide trigonometric and hyperbolic functions not … Continue reading →

Posted in Excel, Link to dll, Maths, Newton, UDFs | Tagged , , , , , , | 2 Comments

Trigonometric Functions in VBA – Update

Posted on 06/12/2008 by dougaj4

In this post from February a set of VBA trigonometric functions were presented, using the derivations given on the Microsoft Developer Network site: Derived Math Functions Unfortunately two of the functions were wrong; the correct versions are shown below: Inverse Secant … Continue reading →

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

Linking Excel to Fortran – 2

Posted on 04/12/2008 by dougaj4

In this post the procedures described for C++ here will be replicated for Fortran: The spreadsheet, fortran source code, and compiled dll described in this code may be downloaded from Cubic.zip As always, it is better to use the downloaded code, … Continue reading →

Posted in Excel, Fortran, Link to dll, Maths, UDFs, Uncategorized, VBA | Tagged , , , , , | 23 Comments

Finding Prime Numbers with Excel, and using Array Formulas

Posted on 18/11/2008 by dougaj4

Download Primes.zip. Several of the puzzles at Project Euler (see previous post) require the finding of prime numbers, for instance what is the 10,001th prime number?  Searching the Web for some ready made solutions I found this array formula at … Continue reading →

Posted in Arrays, Excel, Maths, Newton, UDFs, VBA | Tagged , , , , | 28 Comments