This is a descriptions of the files needed for BEM (Boundary element method) to solve the 2D Laplace equation. (Which needs to be modified to solve the 2D poisson’s equation).

By Nasser Abbasi

Sept 7, 2006

First, this again the WORD document send by Professor Atluri called PoissonBIE.doc for reference.

Now for the FORTRAN code.

The code needed is a little confusing. There are 2 sets of files on the site

http://www.boundary-element-method.com/

VERSION DEMO

This is a set of files DEMO files, which can be found at

http://www.boundary-element-method.com/laplace/ I copied the needed files and here they are

manual_codes_libem2.for

manual_codes_libem2_t.for (MAIN)

manual_codes_l2lc.for

manual_codes_gls.for

manual_codes_geom2d.for

These file do compile OK, and could be run. Here is an example output.txt

This is the WINDOWS EXECUTABLE generated. MAIN.EXE

This is the file I used to compile these. build_demo.sh

VERSION non-demo

From http://www.boundary-element-method.com/laplace/manual/chap1/index.htm

I copied the needed files and here they are

L2LC.FOR

L2LC_T.FOR (the main)

manual_codes_geom2d.for

But these requires NAG library to build. (see below for more information if you want to build these sets of files).

This is the file I used to build these files build.sh

This is the error I get

$ ./build.sh

/cygdrive/c/DOCUME~1/win/LOCALS~1/Temp/ccIuW5W7.o:l2lc_t.for:(.text+0x13ad): undefined reference to `_d01baz_'

/cygdrive/c/DOCUME~1/win/LOCALS~1/Temp/ccIuW5W7.o:l2lc_t.for:(.text+0x13b2): undefined reference to `_d01bbf_'

collect2: ld returned 1 exit status

The problem is that the main program (L2LC_T.FOR) uses NAG routines, which you need. It uses the routines D01BAZ and D01BBF, in NAG library mark 21. see

http://www.nag.com/numeric/fl/FLdescription.asp

which one can download for trial here

http://www.nag.com/downloads/fldownloads.asp

(If someone has access to NAG library, they can try to build these files).

Nasser