ProjectDoc < FST

FST Web>FstQuickTour>ProjectDoc (2018-04-27, MichaelRiley) (raw view)

---+ Project

---++ Description
This operation projects an FST onto its domain or range by either
copying each arc's input label to its output label or vice versa.

---++ Usage
<verbatim>
enum ProjectType { PROJECT_INPUT, PROJECT_OUTPUT };
</verbatim>

|<verbatim>
template<class Arc>
void Project(MutableFst<Arc> *fst, ProjectType type);
</verbatim> |  |
|<verbatim>
template <class Arc> ProjectFst<Arc>::
ProjectFst(const Fst<Arc> &fst, ProjectType type);
</verbatim> | %DOX{fst::ProjectFst[%H%]}% |
|<verbatim>
fstproject [--opts] a.fst out.fst
  --project_output: Project on output (def false)
</verbatim> |  |

---++ Examples

---+++ =A=:

%ATTACHURL%/project1.jpg

---+++ =&pi;<sub>1</sub>(A)=:

%ATTACHURL%/project2.jpg

<verbatim>
Project(&A, PROJECT_INPUT);
ProjectFst<Arc>(A, PROJECT_INPUT);
fstproject a.fst out.fst
</verbatim>

---+++ =&pi;<sub>2</sub>(A)=:

%ATTACHURL%/project3.jpg

<verbatim>
Project(&A, PROJECT_OUTPUT);
ProjectFst<Arc>(A, PROJECT_OUPUT);
fstproject --project_output=true a.fst out.fst
</verbatim>

---++ Complexity

=Project=: 
   * TIme: _O(V + E)_
   * Space: _O(1)_ %BR%
where _V_ = # of states and _E_ = # of arcs.

=ProjectFst:= 
   * Time: _O(v + e)_
   * Space: _O(1)_ %BR% 
where _v_ = # of states visited, _e_ = # of arcs visited
Constant time and to visit an input state or arc is assumed and exclusive of [[FstAdvancedUsage#FstCaching][caching]].


-- Main.MichaelRiley - 1 Jul 2007

Attachments

Topic attachments
I	Attachment	History	Action	Size	Date	Who
jpg	project1.jpg	r2 r1	manage	11.1 K	2007-07-02 - 03:09	MichaelRiley
jpg	project2.jpg	r2 r1	manage	10.3 K	2007-07-02 - 03:09	MichaelRiley
jpg	project3.jpg	r2 r1	manage	10.5 K	2007-07-02 - 03:10	MichaelRiley

Topic revision: r4 - 2018-04-27 - MichaelRiley