Provided by: libbio-perl-perl_1.7.8-1_all
NAME
Bio::Matrix::PSM::IO - PSM parser
SYNOPSIS
use Bio::Matrix::PSM::IO; my $psmIO= Bio::Matrix::PSM::IO->new(-file=>$file, -format=>'transfac'); my $release=$psmIO->release; #Using Bio::Matrix::PSM::PsmHeader methods my $release=$psmIO->release; while (my $psm=$psmIO->next_psm) { my %psm_header=$psm->header; my $ic=$psm_header{IC}; my $sites=$psm_header{sites}; my $width=$psm_header{width}; my $score=$psm_header{e_val}; my $IUPAC=$psm->IUPAC; } my $instances=$psm->instances; foreach my $instance (@{$instances}) { my $id=$instance->primary_id; }
DESCRIPTION
This module allows you to read DNA position scoring matrices and/or their respective sequence matches from a file. There are two header methods, one belonging to Bio::Matrix::PSM::IO::driver and the other to Bio::Matrix::PSM::Psm. They provide general information about the file (driver) and for the current PSM result (Psm) respectively. Psm header method always returns the same thing, but some values in the hash might be empty, depending on the file you are parsing. You will get undef in this case (no exceptions are thrown). Please note that the file header data (commenatries, version, input data, configuration, etc.) might be obtained through Bio::Matrix::PSM::PsmHeader methods. Some methods are driver specific (meme, transfac, etc.): meme: weight mast: seq, instances If called when you parse a different file type you will get undef. For example: my $psmIO= Bio::Matrix::PSM::IO->new(file=>$file, format=>'transfac'); my %seq=$psmIO->seq; will return an empty hash. To see all methods and how to use them go to Bio::Matrix::PSM::PsmHeaderI. See also Bio::Matrix::PSM::PsmI for details on using and manipulating the parsed data. The only way to write PFM/PWM is through masta module (something like fasta for DNA matrices). You can see an example by reading Bio::Matrix::PSM::IO::masta documentation.
See also
Bio::Matrix::PSM::PsmI, Bio::Matrix::PSM::PsmHeaderI, Bio::Matrix::PSM::IO::masta
FEEDBACK
Mailing Lists User feedback is an integral part of the evolution of this and other Bioperl modules. Send your comments and suggestions preferably to one of the Bioperl mailing lists. Your participation is much appreciated. bioperl-l@bioperl.org - General discussion http://bioperl.org/wiki/Mailing_lists - About the mailing lists Support Please direct usage questions or support issues to the mailing list: bioperl-l@bioperl.org rather than to the module maintainer directly. Many experienced and reponsive experts will be able look at the problem and quickly address it. Please include a thorough description of the problem with code and data examples if at all possible. Reporting Bugs Report bugs to the Bioperl bug tracking system to help us keep track the bugs and their resolution. Bug reports can be submitted via the web: https://github.com/bioperl/bioperl-live/issues
AUTHOR - Stefan Kirov
Email skirov@utk.edu
APPENDIX
new Title : new Usage : my $psmIO = Bio::Matrix::PSM::IO->new(-format=>'meme', -file=>$file); Function: Associates a file with the appropriate parser Throws : Throws if the file passed is in HTML format or if some criteria for the file format are not met. See L<Bio::Matrix::PSM::IO::meme> and L<Bio::Matrix::PSM::IO::transfac> for more details. Example : Returns : psm object, associated with a file with matrix file Args : hash fh Title : fh Usage : $obj->fh Function: Get a filehandle type access to the matrix parser Example : $fh = $obj->fh; # make a tied filehandle $matrix = <$fh>; # read a matrix object Returns : filehandle tied to Bio::Matrix::PSM::IO class Args : none _load_format_module Title : _load_format_module Usage : *INTERNAL Matrix::PSM::IO stuff* Function: Loads up (like use) a module at run time on demand _guess_format Title : _guess_format Usage : $obj->_guess_format($filename) Returns : guessed format of filename (lower case) Args : filename next_psm Title : next_psm Usage : my $psm=$psmIO->next_psm(); Function: Reads the next PSM from the input file, associated with this object Throws : Throws if there ara format violations in the input file (checking is not very strict with all drivers). Example : Returns : Bio::Matrix::PSM::Psm object Args : none _parseMatrix Title : _parseMatrix Usage : Function: Parses the next site matrix information in the meme file Throws : Example : Internal stuff Returns : hash as for constructing a SiteMatrix object (see SiteMatrixI) Args : string _parseInstance Title : _parseInstance Usage : Function: Parses the next sites instances from the meme file Throws : Example : Internal stuff Returns : Bio::Matrix::PSM::SiteMatrix object Args : array references _parse_coordinates Title : _parse_coordinates Usage : Function: Throws : Example : Internal stuff Returns : Args : header Title : header Usage : my %header=$psmIO->header; Function: Returns the header for the PSM file, format specific Throws : Example : Returns : Hash or a single string with driver specific information Args : none _make_matrix Title : _make_matrix Usage : Function: makes a matrix from 4 array references (A C G T) Throws : Example : Returns : SiteMatrix object Args : array of references(A C G T)