From: Bill Harlan To: sep@sep.Stanford.EDU Subject: interactive program octave, for matrix algebra Date: Wed, 12 Jul 1995 18:13:34 -0700 Wed Jul 12 17:57:48 PDT 1995 Sep, I just installed the interactive utility "octave" on oas, which works like matlab for linear algebra manipulations. The program internally uses LINPACK, EISPACK and many other standard libraries. The package is PUBLIC DOMAIN, yeah! Here is an example. Type "octave" then a=[1,2;3,4] b=inv(a) c=a*b [u,s,v] = svd(a) for the following results: octave:1> a=[1,2;3,4] a = 1 2 3 4 octave:2> b=inv(a) b = -2.00000 1.00000 1.50000 -0.50000 octave:3> c=a*b c = 1.00000 0.00000 0.00000 1.00000 octave:4> [u,s,v] = svd(a) u = -0.40455 -0.91451 -0.91451 0.40455 s = 5.46499 0.00000 0.00000 0.36597 v = -0.57605 0.81742 -0.81742 -0.57605 The latter is an SVD decomposition. You have all the usual factorizations available, along with most algebraic manipulations of matrices by symbol. You can plot the results too. The program has all documentation available interactively as info files. Type "octave", then "help -i" and see if you can figure out how to read the documentation. I also have postscript documents in big manual: /homes/oldsep/harlan/src/octave-1.1.1/doc/octave.ps reference card: /homes/oldsep/harlan/src/octave-1.1.1/doc/refcard-letter.ps Bill Harlan Email: harlan@sep.stanford.edu (forwarded) Currently: Geophysics, SEP #367 Mitchell Bldg. Stanford University, CA 94305 phone: 415-723-2263; fax: 415-723-0683 After Sept. 1, 1995: Conoco Inc. (1000 S. Pine) P.O. Box 1267 (4449 RW) Ponca City, OK 74602 phone: 405-767-6053; fax: 405-767-2887 Permanent: P.O. Box 442; Ponca City OK 74602-0442 http://sepwww.stanford.edu/oldsep/harlan/index.html