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  • angus1024
    Junior Member
    • Oct 2015
    • 4

    #1

    Where is documentation for Velvet software assembly please.

    Greetings,

    I ask very newbi questions.

    I am trying to understand how to use Velvet (parameters and understand the output) and seek documentation, have read the manual (maybe 21 pages) but thats all I can find.

    Currently, as a test, I try to assemble about 500bp from a very well defined fastq file and do not understand the velvet output. The relevant file (I understand) is called 'LastGraph' containing about 12 contigs and 18 lines starting with the word 'ARC'. I expected a single contig. I would guess a graph could be constructed with these 12 contigs as Vertices and the 18 ARCs as edges but I cannot see this. Also the contigs are pairs which I imagine are somehow (reverse) complemented - but I also do not see this.

    Any comments welcome (especially about LastGraph format/'meaning') and pointers to documentation. I have spent maybe 2 days on this and put in effort and seem to be at a dead end.

    Thanks
    angus1024
  • turnersd
    Senior Member
    • May 2011
    • 115

    #2
    You might try the protocol. Maybe do a little searching around before posting.

    The Velvet de novo assembler was designed to build contigs and eventually scaffolds from short read sequencing data. This protocol describes how to use Velvet, interpret its output and tune its parameters for optimal results. It also covers ...

    Comment

    • angus1024
      Junior Member
      • Oct 2015
      • 4

      #3
      Originally posted by turnersd View Post
      You might try the protocol. Maybe do a little searching around before posting.
      http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2952100/
      Thanks TurnerSD, appreciated. I had put in effort and try not to waste peoples time.

      I'd already seen this one - will reread it including the references in case I missed something.

      I still do not understand the knowledge embedded within the Velvet output file called LastGraph.

      Thanks
      angus1024

      Comment

      • Ancestro
        Member
        • Oct 2015
        • 15

        #4
        Maybe you might look at this



        LastGraph explanation Retrieved from the same doc. http://imgur.com/R9TZBWN

        Comment

        • angus1024
          Junior Member
          • Oct 2015
          • 4

          #5
          Thank you

          Thank you very much indeed Ancestro. Just the info I was after.

          But I had read this document and missed the section !!! I really was at a dead end. Apologies for taking up your time and I am grateful.

          Comment

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