Today’s downloads collect several spreadsheets related to solution of simultaneous equations and matrix arithmetic, some of which were presented previously as part of the ALGLIB library (Daily Download 13).

Solving simultaneous equations described how to solve simultaneous equations using the Excel MInverse and MMult functions, and provided two VBA functions for solution of simultaneous equations.

In Solving simultaneous equations – Fortran dll the VBA function was converted to a compiled Fortran dll, offering much better performance, but see Distributing Silverfrost Fortran Applications for details of installation of the necessary run-time library, and note that this function may not work on Windows 7 systems*.
Download file: http://interactiveds.com.au/software/Simultaneous.zip

* Edit 8th Oct 2012 – “Windows Vista” changed to “Windows 7”; see also comment from cjberg at https://newtonexcelbach.wordpress.com/2008/12/01/linking-excel-to-fortran/#comment-4622

ALGLIB VBA matrix arithmetic functions were described in Installing AlgLib with Excel VBA, and c++ compiled versions in Compiled AlgLib Matrix Functions for Excel.  The functionality was further improved with a C# compiled version of the latest version of the library, including support for sparse matrices; see Compiled Matrix Functions for Excel.
Download files: http://interactiveds.com.au/software/AL-Matrix-xlsb.zip
http://interactiveds.com.au/software/AL-Matrix-xls.zip
http://interactiveds.com.au/software/AL-Matrixdll2.zip
http://www.interactiveds.com.au/software/Matrixdll-c%23.zip (latest version)
See also http://interactiveds.com.au/software/AL-Spline-Matrix03.zip and
http://interactiveds.com.au/software/AL-Spline-Matrix07.zip which also include the VBA matrix functions.

Solution of linear equations with compiled ALGLIB function