Bio::SeqIO::largefasta - method i/o on very large fasta sequence files


Do not use this module directly. Use it via the Bio::SeqIO class.


This object can transform Bio::Seq objects to and from fasta flat file databases.

This module handles very large sequence files by using the Bio::Seq::LargePrimarySeq module to store all the sequence data in a file. This can be a problem if you have limited disk space on your computer because this will effectively cause 2 copies of the sequence file to reside on disk for the life of the Bio::Seq::LargePrimarySeq object. The default location for this is specified by the File::Spec->tmpdir routine which is usually /tmp on UNIX. If a sequence file is larger than the swap space (capacity of the /tmp dir) this could cause problems for the machine. It is possible to set the directory where the temporary file is located by adding the following line to your code BEFORE calling next_seq. See Bio::Seq::LargePrimarySeq for more information.

    $Bio::Seq::LargePrimarySeq::DEFAULT_TEMP_DIR = 'newdir';


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Please direct usage questions or support issues to the mailing list:

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.

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AUTHORS - Jason Stajich



The rest of the documentation details each of the object methods. Internal methods are usually preceded with a _


 Title   : next_seq
 Usage   : $seq = $stream->next_seq()
 Function: returns the next sequence in the stream
 Returns : A Bio::Seq::LargePrimarySeq object
 Args    : NONE


 Title   : write_seq
 Usage   : $stream->write_seq(@seq)
 Function: writes the $seq object into the stream
 Returns : 1 for success and 0 for error
 Args    : Bio::Seq object