Re: [Lapackpp-devel] Latridiagatdouble

[Christian S. <sti...@tu...>]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Do bi schrieb:
> Hi. You briefly explained with enough code how to create a tridiagonal
> matrix on
> http://lapackpp.sourceforge.net/html/classLaTridiagMatDouble.html#_details
> which is 
>  LaVectorDouble newdiag(N);
>   newdiag(0) = ...;
>   LaTriagMatDouble triagmat(N);
>   triagmat.diag(0).inject(newdiag); // correct
>   // but don't write this:
>   triagmat.diag(0) = newdiag; // wrong!
>   and easily understood and very helpful. Can you please write a similar
> size of code to solve a tridiagonal matrix?

Sure:

#include <trfd.h> // for LaTridiagFactDouble class

// define A
LaTridiagMatDouble A(N);
A.diag(0).inject(...); // fill the matrix with values
// define X and B
LaGenMatDouble B(N,1);
B = ...; // fill B with values from somewhere
// To solve Ax=b:
LaTridiagFactDouble Afact;
LaGenMatDouble X(N,1);
LaTridiagMatFactorize(A, Afact); // calculate LU factorization
LaLinearSolve(Afact, X, B); // solve; result is in X

Regards,

Christian

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.2.1 (MingW32)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iQCVAwUBRNhIn2XAi+BfhivFAQLS0wP+MZEGreWLkbBGxk2EGVHAY86kL4YDiXfO
uGgCXCu31hy/1kXRQI32GNpvZEhTgeiP3kA232Y651MBrXY1LjAgAMEcYKHf9DT+
OzUFsvNXnm4cTzepuphgr1jyqiDL0VjbQBmLdOf/e1RfB/kmxEmB/A4GQPAL3Lvw
yueID2dzOPg=
=aggs
-----END PGP SIGNATURE-----