Shell Programming and Scripting

I have a file that looks like this:

Code:

id window BV
1 1 0.5
1 2 0.2
1 3 0.1
2 1 0.5
2 2 0.1
2 3 0.2
3 1 0.4
3 2 0.6
3 3 0.8

Using awk, how would I get the average BV for window 1? Output like this:

Code:

window avgBV
1 0.47
2 0.23
3 0.37

How does your output correspond to your input?

The output is showing the average BV for window 1, 2 etc.

So the second column? Your suggested output does not seem to correspond to averages..
The average for window 1 is 0.466667 for example ( ( 0.5 + 0.5 + 0.4 ) / 3 )...

fixed

Not entirely. Is this homework?

Not homework, but research problem. I am a PhD student in quantitative animal genomics. I am a geneticist, but working on learning unix programming. I have large output files (500 mb) that are analyzing effects from 50,000 DNA markers in 2000 animals. The program divides the genome into 1,000,000 base pair segments called a 'window'. I need to extract the breeding value (BV) for each window averaged across the 2000 animals. The table above is an example of what my output looks like. I apologize if I am not meeting the formatting requirements for this forum, it is my first post. I have been unable to find an awk solution anywhere else, hence my post.

edit: I should clarify that even though I am a student this is not for a class, but real data that is part of my research.