Shell Programming and Scripting

Hi all,

I have a file which looks like:

Code:

0   1.1985506
1   1.2237930
2   1.2159038
3   1.2668828
4   1.2650216
5   1.2474344
6   1.2817688
7   1.2721698
8   1.2665005
9   1.2826315
10  1.2797879
11  1.3201736
12  1.3116595
13  1.3361583
14  1.3309238
15  1.3521332
16  1.3593159
17  1.3558449
18  1.3792990
19  1.3990164
20  1.4039725
21  1.4026414
22  1.4141786
23  1.4655373
24  1.4627539
25  1.4684621
26  1.4994614
27  1.4573526
28  1.4736820
29  1.4868084
30  1.4942920

and i need to get the closest values that result from successive increments in second column (say for example 0.2) starting from the first value until the end of the file is reached, so my output would be in this case:

Code:

0   1.1985506
19  1.3990164

Note that the value resulting from the addition of the last matched value (1.3990164) and the increment (0.2), i.e. 1.5990164, is greater than the last value of the file (1.4942920), so that's why 1.3990164 is the last printed value.

Is this possible to do? I would appreciate an awk, perl or python suggestion, since those are the programing languages I use at work.

Code:

#! /bin/sh

awk '
BEGIN {
	delta=0.2

	# process first line
	getline
	value=$2
	print
}
{
	if ( $2-value > delta ) {
		print 
		value=$2
	}
}' input

Nice! Thank you!