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  • blast evalue strange behaviour

    hello, I am experiencing a strange behaviour of blastn with the option "evalue":

    $ blastn -task blastn -query _p -db genome.fa -outfmt 6
    snoRNA_CD33 Chromosome_5 76.85 108 19 5 4 109 2773492 2773389 4e-11 66.2
    snoRNA_CD33 Chromosome_2 91.30 23 1 1 45 66 7139854 7139876 2.9 30.1
    snoRNA_CD33 Chromosome_1 94.74 19 1 0 28 46 3318593 3318575 2.9 30.1

    good, found a hit at 4e-11 evalue


    $ blastn -task blastn -query _p -db genome.fa -outfmt 6 -evalue 1
    snoRNA_CD33 Chromosome_5 76.85 108 19 5 4 109 2773492 2773389 4e-11 66.2

    same hit setting the evalue threshold at 1, as expected


    $ blastn -task blastn -query _p -db genome.fa -outfmt 6 -evalue 0.1
    $


    no result! why? 4e-11 is still less than 0.1....

    any idea?

  • #2
    Have you tried expressing 0.1 as 1e-01 instead?

    Comment


    • #3
      Originally posted by mastal View Post
      Have you tried expressing 0.1 as 1e-01 instead?
      yes, same result

      Comment


      • #4
        Are you using the latest version, BLAST+ 2.2.29 currently?

        If so, I suggest you email the BLAST team with a bug report (and ideally offer to provide your data as a test case),

        Comment


        • #5
          Originally posted by maubp View Post
          Are you using the latest version, BLAST+ 2.2.29 currently?

          If so, I suggest you email the BLAST team with a bug report (and ideally offer to provide your data as a test case),
          ok, it looks like it happened only with 2.2.27, with the new version everything is ok, thanks

          Comment

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