suppose u have a file 
1  0.4 2 
1  0.2  -5  
1  0.1  -18  
1  0.11 7  
0 0.13  10 
0  0.22  11
 
##</code><code>##

 
 From the  second column and third column , u want to show at different intervals keeping second  column fixed  and change the interval in the third column. 
Like at less than 0.01 from the scond column and <9 and <8 how many numbers are there in one output 
then again keeping 0.01 same as above and then <8 and >7 how many numbers ...respectively 
 Then change the interval from less than 0.01 to >0.01 and less tahn 0.02 in the second column and again start from the third column with  <9 and >8 respectively

##</code><code>##

 
#!/usr/bin/perl -w


open (FILE,"$ARGV[0]") or die;
open (WRITE,">ca_0.01_1.txt");
@list =<FILE>;
close (FILE);
my $f =join ("",@list);

my @t = split ("\n",$f);

foreach (@t) {

my @x = split("\t",$_);

 if(($x[1]<=0.01) && ($x[0]=="0"))   {
 next if  ( $x[2]>=-8);
 next if  ($x[2]<-9);
#next if ($x[0]!=0);
#next if ($x[0]!=1);
print WRITE @x,"\n";

}
}
close (WRITE);
exit;