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BBMap output meaning
Hi All 

Does anyone understand the following top lines from BBMap ihist output;
I use some previous biostars to run it but can't get what are the `#InsertSize` and `Count`.

Does it mean the first insert size is 77? Then can we have insert sizes = 1 as in the end of the output?

    Here is my output:
    #Mean   193.157
    #Median 168
    #Mode   145
    #STDev  396.478
    #PercentOfPairs 92.468
    #InsertSize     Count
    1       77
    2       87
    3       105
    4       107
    5       98
    6       92
    7       94
    8       103
    9       121
    10      112
   ..... .... ... .. 


    29754   1
    29919   1
    30005   1
    30062   1
    30481   1
    30732   1
    31142   1
bbmap rnaseq

Can you provide the full command line used?

I used the following command, found it somewhere in biostars:

 ./bbmap.sh -Xmx50g  in1=Sread1.fastq.gz in2=Sread2.fastq.gz ihist=histmap1m.txt reads=1000000 ref=human_genome.fa

I am not sure why you have insert sizes that small and with quite a few counts as well. Has this data been trimmed? You probably should have set a minlen=25 when you trimmed the data to avoid getting very short reads.

Sorry to bother again. But which column is the insert sizes? the count column? These are the raw data before doing anything.

#InsertSize     Count

First column should be insert size and second column is count of fragments with that insert size.

Have you scanned/trimmed this data? Can you try that?

I will tag @Brian Bushnell on this thread so he can offer his take. Please be aware that he has been busy of late and it may be a few days before he may look at this.

Edited: Thanks genomax, much appreciated ! I will use the trimmed data and see the difference. But this also mean we have too big insert sizes at end? Does this make sense?

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