Mercurial > octave-antonio

comparison doc/interpreter/sparse.txi @ 5704:3d8d8ce93c2c

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
[project @ 2006-03-21 21:53:56 by jwe]
author jwe
date Tue, 21 Mar 2006 21:53:56 +0000
parents 233d98d95659
children 0a26811c98be
comparison
equal deleted inserted replaced
5703:1199fc86582d 5704:3d8d8ce93c2c
325 325
326 There are several graphical means of finding out information about 326 There are several graphical means of finding out information about
327 sparse matrices. The first is the @dfn{spy} command, which displays 327 sparse matrices. The first is the @dfn{spy} command, which displays
328 the structure of the non-zero elements of the 328 the structure of the non-zero elements of the
329 matrix. @xref{fig:spmatrix}, for an exaple of the use of 329 matrix. @xref{fig:spmatrix}, for an exaple of the use of
330 @dfn{spy}.More advanced graphical information can be obtained with the 330 @dfn{spy}. More advanced graphical information can be obtained with the
331 @dfn{treeplot}, @dfn{etreeplot} and @dfn{gplot} commands. 331 @dfn{treeplot}, @dfn{etreeplot} and @dfn{gplot} commands.
332 332
333 @float Figure,fig:spmatrix 333 @float Figure,fig:spmatrix
334 @ifset INCLUDE_FIGURES
334 @ifinfo 335 @ifinfo
335 @example 336 @example
336 @include spmatrix.txt 337 @include spmatrix.txt
337 @end example 338 @end example
338 @end ifinfo 339 @end ifinfo
339 @ifset htmltex 340 @ifset htmltex
340 @image{spmatrix,8cm} 341 @image{spmatrix,8cm}
341 @end ifset 342 @end ifset
343 @end ifest
342 @caption{Structure of simple sparse matrix.} 344 @caption{Structure of simple sparse matrix.}
343 @end float 345 @end float
344 346
345 One use of sparse matrices is in graph theory, where the 347 One use of sparse matrices is in graph theory, where the
346 interconnections between nodes is represented as an adjacency 348 interconnections between nodes is represented as an adjacency
365 the nodes are given in the n-by-2 matrix @code{xy}. 367 the nodes are given in the n-by-2 matrix @code{xy}.
366 @ifset htmltex 368 @ifset htmltex
367 @xref{fig:gplot}. 369 @xref{fig:gplot}.
368 370
369 @float Figure,fig:gplot 371 @float Figure,fig:gplot
372 @ifset INCLUDE_FIGURES
370 @image{gplot,8cm} 373 @image{gplot,8cm}
374 @end ifset
371 @caption{Simple use of the @dfn{gplot} command.} 375 @caption{Simple use of the @dfn{gplot} command.}
372 @end float 376 @end float
373 @end ifset 377 @end ifset
374 378
375 The dependencies between the nodes of a Cholesky factorization can be 379 The dependencies between the nodes of a Cholesky factorization can be
577 581
578 @xref{fig:simplematrix}, for an example of the structure of a simple 582 @xref{fig:simplematrix}, for an example of the structure of a simple
579 positive definite matrix. 583 positive definite matrix.
580 584
581 @float Figure,fig:simplematrix 585 @float Figure,fig:simplematrix
586 @ifset INCLUDE_FIGURES
582 @ifinfo 587 @ifinfo
583 @example 588 @example
584 @include spmatrix.txt 589 @include spmatrix.txt
585 @end example 590 @end example
586 @end ifinfo 591 @end ifinfo
587 @ifset htmltex 592 @ifset htmltex
588 @image{spmatrix,8cm} 593 @image{spmatrix,8cm}
594 @end ifset
589 @end ifset 595 @end ifset
590 @caption{Structure of simple sparse matrix.} 596 @caption{Structure of simple sparse matrix.}
591 @end float 597 @end float
592 598
593 The standard Cholesky factorization of this matrix, can be 599 The standard Cholesky factorization of this matrix, can be
642 arguments as r@code{[r, p, q] = chol(A); spy(r)}. 648 arguments as r@code{[r, p, q] = chol(A); spy(r)}.
643 649
644 @ifset HAVE_CHOLMOD 650 @ifset HAVE_CHOLMOD
645 @ifset HAVE_COLAMD 651 @ifset HAVE_COLAMD
646 @float Figure,fig:simplechol 652 @float Figure,fig:simplechol
653 @ifset INCLUDE_FIGURES
647 @ifinfo 654 @ifinfo
648 @example 655 @example
649 @include spchol.txt 656 @include spchol.txt
650 @end example 657 @end example
651 @end ifinfo 658 @end ifinfo
652 @ifset htmltex 659 @ifset htmltex
653 @image{spchol,8cm} 660 @image{spchol,8cm}
654 @end ifset 661 @end ifset
662 @end ifset
655 @caption{Structure of the un-permuted Cholesky factorization of the above matrix.} 663 @caption{Structure of the un-permuted Cholesky factorization of the above matrix.}
656 @end float 664 @end float
657 665
658 @float Figure,fig:simplecholperm 666 @float Figure,fig:simplecholperm
667 @ifset INCLUDE_FIGURES
659 @ifinfo 668 @ifinfo
660 @example 669 @example
661 @include spcholperm.txt 670 @include spcholperm.txt
662 @end example 671 @end example
663 @end ifinfo 672 @end ifinfo
664 @ifset htmltex 673 @ifset htmltex
665 @image{spcholperm,8cm} 674 @image{spcholperm,8cm}
675 @end ifset
666 @end ifset 676 @end ifset
667 @caption{Structure of the permuted Cholesky factorization of the above matrix.} 677 @caption{Structure of the permuted Cholesky factorization of the above matrix.}
668 @end float 678 @end float
669 @end ifset 679 @end ifset
670 @end ifset 680 @end ifset
1029 @ifset htmltex 1039 @ifset htmltex
1030 @ifset HAVE_CHOLMOD 1040 @ifset HAVE_CHOLMOD
1031 @ifset HAVE_UMFPACK 1041 @ifset HAVE_UMFPACK
1032 @ifset HAVE_COLAMD 1042 @ifset HAVE_COLAMD
1033 @float Figure,fig:femmodel 1043 @float Figure,fig:femmodel
1044 @ifset INCLUDE_FIGURES
1034 @image{grid,8cm} 1045 @image{grid,8cm}
1046 @end ifset
1035 @caption{Example finite element model the showing triangular elements. 1047 @caption{Example finite element model the showing triangular elements.
1036 The height of each vertex corresponds to the solution value.} 1048 The height of each vertex corresponds to the solution value.}
1037 @end float 1049 @end float
1038 @end ifset 1050 @end ifset
1039 @end ifset 1051 @end ifset