Hi guys,
I need some guidance on a code i wrote. I am trying to implement a sliding-window technique, in which I have to increment one "for" loop(dependent on the index of larger loop) within another "for" loop.
Now the code i have is 
 
for ($i=$analysisstartposn-1 ; $i<($seqlength-$windowsize) ; $i+$steps
+ize)
{
   for ($j = $i ; $j < $i+$windowsize ; $j++)
   {
        print OUTFILE "$i\t$j\n";
   }
}

[download]
I use "strict" and "diagnostics" in my script and i get an error that says "useless use of addition (+) in void context at line #(where the for loop with $j is present in the above code)"
If i have a step-size of 2 and a window size of 4, the output i need has to be in the form of:
i j
0 0
0 1
0 2
0 3
2 2
2 3
2 4
2 5
......... and so on

but the output i get, from the above code is in a way that $i does not increase, only $j resets and then increases at the end of its loop. I mean its like this
i j
0 0
0 1
0 2
0 3
0 0
0 1
0 2
0 3
..... and so on

Any help would be appreciated
Thanks in advance

Krish

In reply to Incrementing one "for" loop within another "for" loop by krish28

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