Hi ! Experts...

I just wanted to know whether it is possible in scripting...to do interpolation....

if so....have a look on my data file

I need temperature and salinity value with a bin size of 0.5 m

output looks somewhat like this

dep   temp  sal
0.5     25     0.077
1        25     0.077
1.5
2
2.5
-
-
-
8.5     25     0.16

                mask  depth
1:   .... 1:  1.000  0.789  ---backward derivative
2     /   2:  1.000  0.789  ---forward derivative
3     /   3:  1.000  0.789
4     /   4:  1.000  0.789
5     /   5:  1.000  0.789
23    /  23:   ....    0.789
24    /  24:   ....    0.790
25    /  25: 1.000 0.790
26    /  26: 1.000 0.790

Attached Files

ctd001_ins1_04-08-07_1100.txt (20.7 KB, 6 views)

I don't understand what you're trying to achieve. Could you please explain a bit more.

Sometimes, Understanding a question is much harder than providing a solution.

Cheers,
Korean

Try to understand..

consider 1st column, you can find duplicate values 0.789 repeated for about 22 times, but in second and third column values are varying, because of duplicates in 1st column, I have to take average of 2nd and 3rd values (22 values), so what script has to do is whenever it finds duplicate value it has to do averaging..

example : let me take first one sample input here

column 1 column 2  
1                 20.2
1                 21.2        -------> 3 values in 1st column are same 
1                 22.3                   so I need average of column 2
2                 22.5                   average will be 21.13
3                 25.9
4                 26.8
4                 26.9
4                 26.7

column 1 column 2
1               21.13
2               22.5
3               25.9
4               26.8

$ cat file
1 20.2
1 21.2
1 22.3
2 22.5
3 25.9
4 26.8
4 26.9
4 26.7

$ awk 's != $1 && NR > 1{print s,a/X[s];a=0}{a+=$2;s=$1;X[$1]++}END{print s,a/X[s]}' file
1 21.2333
2 22.5
3 25.9
4 26.8

I'm not sure I understand either. You want to generate data points every 0.5 m. Depth ranging from 0.789 to 8.305 you will get sth. like 16 data points, say 1, 1.5, ..., 8.5. So why don't you collect the temperatue and salinity into avarages around those abcissa values?
Why do you crack a nut with a sledge hammer, averaging 23 values for 0.789m, when everything will disappear in a large lump sum at 1.0m?
BTW, nit-picking, you can have difference quotients on those columns but no derivatives. And, I think it would be helpful to use one single sample file to discuss and attach, so col 1 would be col 1 everywhre.

And, finally answering your introductory question, yes, I'm pretty sure you can do (some degree of) interpolation in scripts.

Dear Pamu, if you have time can you please explain 2nd line (awk) of script.. please