PERL - extracting the max and min value from sets of data

This should get you started.

The postions where all in ascending order, so I reorded them in case they are not always in sequence.

I'm working from a DATA block for testing but you can easily change this to a file.

Also, the e-value always seems to be the same. I'm using the last one from a set of records with identical Query and Score, but maybe this isn't what you want.

It reads in the file (or block) one line at a time, but the %query_score hash can use quite a lot of memory depending on file size.


my %query_score;
while ( <DATA> )
{
    chomp;
    ($Query,$Score,$E_Value,$Position) = split(/ +/,$_);
    push( @{ $query_score{"$Query:$Score"}{position} },$Position);
    $query_score{"$Query:$Score"}{E_Value} = $E_Value;
   
}

foreach $key ( sort keys %query_score )
{
    ($Query,$Score) = split(/:/,$key);
    @positions =  sort @{ $query_score{$key}{position} };
    $E_Value = $query_score{$key}{E_Value};
    $min = shift(@positions);
    $max = pop(@positions);
    print("$Query \t$Score\t $min\t $max\n");
   
}

__DATA__
At1g01010       775      0.0      4705
At1g01010       775      0.0      4765
At1g01010       775      0.0      4825
At1g01010       775      0.0      4945
At1g01010       775      0.0      4885
At1g01010       775      0.0      5005
At1g01010       775      0.0      5065
At1g01010       557      e-158    3996
At1g01010       557      e-158    4056