Hi all,

I have 4018 files each has the latitude and longitude coordinates of daily weather reports, what I would like to do (if possible) is to calculate the number of weather stations within a region for each file. For example all points between latitude -20 and -10 and longitude -70 and -50. Each file (daily report) has a variable number of records

Thanks
Luis

Help us to help you. Provide a sample input file (10-15 lines will do). Construct a sample output file which corresponds to your sample input and post both samples here. With "Before and After" examples we can better understand your needs and also judge if our proposed solution fills those needs.

Daniel B. Martin

All right Daniel,
part of the file I have is like this
77777 -6.47 -35.86 0.00
77777 -2.73 -63.25 0.00
77777 -9.48 -35.85 0.00
77777 -10.49 -40.20 2.40
77777 -9.51 -36.02 0.00
77777 -8.52 -36.03 0.00
77777 -14.52 -64.81 0.00
77777 9.55 -69.24 0.00
77777 3.56 -40.65 0.00
77777 -7.62 -48.39 0.00
77777 -3.57 -68.28 4.10
77777 -4.59 -46.68 8.00
77777 0.59 -62.39 0.70
77777 -34.62 -37.76 0.00
77777 -23.62 -49.15 0.00
77777 -14.62 -67.53 4.60
77777 -16.63 -37.76 0.00
77777 -22.64 -56.02 0.00
77777 -29.67 -35.70 0.00
77777 -9.68 -40.60 0.00
77777 -33.68 -61.98 0.00
77777 -9.69 -65.99 36.70
77777 -5.70 -65.36 10.50
77777 -8.72 -35.89 0.00
77777 -6.75 -37.45 0.00
77777 9.75 -63.19 3.00
77777 -2.76 -66.61 35.70
77777 -13.82 -54.89 0.00
77777 -11.86 -58.25 0.00
77777 -9.87 -56.10 0.00
77777 -13.89 -62.99 0.00
77777 -17.89 -75.75 0.00
77777 -19.93 -63.06 0.00
77777 -25.94 -57.13 1.70
77777 -22.96 -47.67 2.60
77777 -32.97 -36.98 0.00
77777 -30.97 -37.00 0.00
77777 -34.97 -49.99 6.90
77777 -16.99 -47.48 13.80

What I would like is to get the number of occurrences that I have on the second column within -20 and -10 AND on the third column within -70 and -50, that might bring 6, since this is the number of records that match my request

77777 -13.82 -54.89 0.00
77777 -11.86 -58.25 0.00
77777 -13.89 -62.99 0.00
77777 -19.93 -63.06 0.00
77777 -14.62 -67.53 4.60
77777 -14.52 -64.81 0.00

Hope this can help me
Luis

Never mind, found a solution with awk

Thanks anyway, just asking makes my brain to speed up !

Luis

Nice clean solution. However, your problem statement suggests there is more to be done.

You cited "the number of occurrences." This awk enumerates lines which meet certain criteria but does not count them.

You wrote of "the number of weather stations within a region." Where are those weather stations? Are their coordinates (latitude and longitude) in another file? What defines the size and shape of a region? Is a region rectangular or within a specified radius around each station?

awk has good arithmetic capabilities and the solution to a more complex problem could be built around a sequence of them.

Daniel B. Martin

What I was after was that, the only thing I added was

and that gives me what I was looking for, because the region is a rectangle and what I need is to know how many stations do I have in that particular region latitude min=-20, latitude max=-10, longitude min=-70, longitude max=-50. The file content are each station's latitude/longitude, so by counting how many meet this criteria, I'm obtaining my goal, to know for each day (each file) how many reporting stations do I have.

Anyway thanks for your interest Daniel !

Best regards
Luis