Unconfigured Ad

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • lh3
    replied
    This is a flaw in bwa when generating SAM. I will fixed it.

    It is not so easy to generate absolutely correct SAM due to the dependency between fields and between mates. We tried to minimize the dependency in design, but reducing dependency causes inconvenience in other cases. There is always a balance.

    Leave a comment:


  • corthay
    replied
    Thank you for your speedy response.

    I have one more question. I got following results by using bwa(0.4.9), my favorite.
    seq-name#0 69 * 0 0 * * 0 0 (sequence) (quality)
    seq-name#0 133 * 0 0 * * 0 0 (sequence) (quality)

    Both reads do not be mapped but the flag for "the mate is unnmapped" are 0.
    How should I interpret it?

    Leave a comment:


  • jess
    replied
    Thanks Heng. I will try and let you know if I get stuck in something.

    Leave a comment:


  • lh3
    replied
    samtools.pl now updated at SVN:

    Download SAM tools for free. SAM (Sequence Alignment/Map) is a flexible generic format for storing nucleotide sequence alignment. SAMtools provide efficient utilities on manipulating alignments in the SAM format.


    pileup2fq is implemented, similar to maq's cns2fq. Please note that samtools.pl filters based on the RMS mapping quality (-Q) while maq's cns2fq filters on the maximum mapping quality. Also, pileup2fq masks a small region around an potential indel, but maq's cns2fq does not. The overall accuracy looks similar to maq, though.

    Leave a comment:


  • jess
    replied
    ok! So i knw where i ws gng wrong...
    the .aln file shud be put in last after all d options.

    Leave a comment:


  • jess
    replied
    I tried using the -c option,bt the pileup output is same evn widout this option! I gave d command smfink like dis:


    samtools pileup -f ref.fasta aln_sorted.bam -s -c -v >test.pileup

    Let me know wher I m gng Wrong!

    Leave a comment:


  • mikyatope
    replied
    Originally posted by zee View Post
    Is there a way to convert a SAM consensus output (using -c option for pileup) to the old maq-style .cns consensus?

    I have some maq-based pipelines I would like to use on my BWA results.
    maybe it's related.

    Is possible get the consensus sequence in a simple fasta format with SAMtools?

    Leave a comment:


  • jkbonfield
    replied
    I'm not sure if it's the case here, but I've noticed the CIGAR string has major issues if you attempt to include gaps in the clipped sequence.

    Or rather CIGAR works fine I assume, but samtools does not. (It's not really a big issue as the only time I've seen this happen is someone manually trimming an alignment back.)

    Leave a comment:


  • lh3
    replied
    @corthay

    You can convert with "blast2sam.pl -s" to save the sequence in SAM. Currently, samtools cannot parse SAM without sequence, although the specification allows this.

    @jess and zee

    Sorry. I am afraid that you cannot easily convert pileup output to maq-cns. You can call SNPs/indels directly from samtools and in SVN samtools.pl now filters SNPs/indels in the maq-like way. .cns has been replaced with glf, although they contain different information.

    Leave a comment:


  • corthay
    replied
    I would like to generate bam file from blast result of EST.

    Firstly, I made sam file from blast result using blsat2sam.pl in samtools packages.
    Secondly, I have tried to convert from sam file into bam file using "samtools import" but I've got following error.

    Parse error at 1: CIGAR and sequence length are inconsistent.

    seq1 16 chr20 18289430 255 23H426M760H * 0 0 * * AS:i:844 EV:Z:0.0

    Could you give me any idea please ?

    Leave a comment:


  • jess
    replied
    Originally posted by zee View Post
    Is there a way to convert a SAM consensus output (using -c option for pileup) to the old maq-style .cns consensus?

    I have some maq-based pipelines I would like to use on my BWA results.
    Yes, I am looking for the same. Heng li cud u help out plz?

    Leave a comment:


  • lh3
    replied
    X? tags are for aligner specific information. You need to read the documentation of the program that generates these tags.

    Leave a comment:


  • pparg
    replied
    I read through the latest SAM Format Specification on optional fields. But I still don’t understand some cases in the .sam file I got. For instances:
    XT:A:R NM:i:0 X0:i:30406 XM:i:0 XO:i:0 XG:i:0
    XT:A:R NM:i:1 X0:i:2 X1:i:1 XM:i:1 XO:i:0 XG:i:0 MD:Z:3G32
    I just can’t figure out what do those X? fileds mean? I know these are are reserved for local use and re not be formally defined. But what is the point here? What are the types A, i, Z etc for?
    Any hint/ideas would be appreciated.

    Leave a comment:


  • zee
    replied
    Is there a way to convert a SAM consensus output (using -c option for pileup) to the old maq-style .cns consensus?

    I have some maq-based pipelines I would like to use on my BWA results.

    Leave a comment:


  • lh3
    replied
    On behalf of the Java API developers: the Java APIs and command-line tools are formally released here (also linked from http://samtools.sourceforge.net):



    The Java implementation is more flexible than SAMtools-C on sorting/viewing/merging/rmdup. Developers may also find Java APIs are easier to use than the C APIs.

    By the way, Lincoln Stein has implemented initial Perl bindings for the SAM/BAM format, based on the C APIs. This Perl module will become part of BioPerl as well as GBrowse.

    Leave a comment:

Latest Articles

Collapse

  • SEQadmin2
    Cancer Drug Resistance: The Lingering Barrier to Rising Survival
    by SEQadmin2



    Cancer survival rates have significantly increased in the last few decades in the United States, reaching a combined 70% 5-year survival rate by 2021. Behind this number, there are years of research to find new therapies, drug targets, and early detection methods. But there is one core challenge that keeps slowing down these advances, and it’s about drug resistance.

    There is no single reason why many patients don’t respond to treatment as expected. Cancer is...
    Today, 05:17 AM
  • GATTACAT
    Reply to Nine Things a Sample Prep Scientist Thinks About Before Sequencing
    by GATTACAT
    Love this - good data definitely starts from good input, and poor input can only give relatively poor data. I particularly like the mention of Nanodrop/absorbance based methods for quantification. It's such a toss up if you'll get an accurate reading or what amounts to a randomly generated number, and a lot of library/sequencing related issues can be traced back to poor quant.
    07-01-2026, 11:43 AM
  • SEQadmin2
    Nine Things a Sample Prep Scientist Thinks About Before Sequencing
    by SEQadmin2


    I’m not a sequencing expert. I’m a purification scientist who uses NGS to evaluate workflows my group develops. With this perspective, we think about the sample first and the NGS workflow second. The sequencer is an exceptionally honest reporter, but it can only report on what you give it, so whether you get clean, interpretable data from an NGS workflow is largely determined before you begin.

    Here are nine questions we think about, in roughly the order they matter, before...
    06-18-2026, 07:11 AM

ad_right_rmr

Collapse

News

Collapse

Topics Statistics Last Post
Started by SEQadmin2, Yesterday, 11:05 AM
0 responses
7 views
0 reactions
Last Post SEQadmin2  
Started by SEQadmin2, 07-02-2026, 11:08 AM
0 responses
28 views
0 reactions
Last Post SEQadmin2  
Started by SEQadmin2, 06-30-2026, 05:37 AM
0 responses
28 views
0 reactions
Last Post SEQadmin2  
Started by SEQadmin2, 06-26-2026, 11:10 AM
0 responses
27 views
0 reactions
Last Post SEQadmin2  
Working...