how to select, copy columns of different file to form new files

I think you could do this with paste, and possibly join.

paste file1 file2 > temp1
paste temp1 file3 > temp2
paste tmpe2 file4 > final

That should work if the files contain station 1 thru n data in order. If not, you will need to get the files aligned somehow. If the "stattion n" notation is part of every file, you should sort them:

sort -o file1 file1
sort -o file2 file2
... and so forth

Then, you could do join instead of paste as above. join has some tricky options about putting lines in output that don't have a match in the other file, so you may have to read the join man page very carefully and experiment a bit to get what you want.

From your description it sounds like you'd like to iterate through the 4 files, Prec, Tmin, Tmax, and wind and take the column data from each and merge it into a singe file per each column.

The approach

One way to achieve this is by using a Bash for loop, paste and awk. The approach would go something like this:

for i in `seq 8`; do
    ... do stuff ...
done

The primary purpose of this loop would be to step through the columns, 1 through 8.

Pulling out columns

The next bit we need to put together is the ability to pull data from a file, column-wise. One idea would be to use awk to do this.

$ awk '{print $1}' Prec
1
0
0.254
0

We can take this a step further and get it to skip the first line, which is the reference number of the column, like so:

$ awk 'NR>1{print $1}' Prec
0
0.254
0

We can go even further by parameterizing the column we're printing by making it a variable that we pass into awk like so:

$ awk -v a=1 'NR>1{print $a}' wind
0
1.778
1.652
$ awk -v a=2 'NR>1{print $a}' wind
0
1.778
1.653

Puling out columns from multiple files

This bit is probably the least elegant bit to this solution, but I'm an awk noob, so when in doubt, go with a hack.

Here were using the output from multiple awk's which pull the column-wise data from each file, and pasting them together using paste.

Here's 2 of the files, just so it's easier to see.

column #1

$ paste <(awk -v a=1 'NR>1 {print $a}' Prec) <(awk -v a=1 'NR>1 {print $a}' Tmin)
0   -23.349
0.254   -23.682
0   -24.302

column #2

$ paste <(awk -v a=2 'NR>1 {print $a}' Prec) <(awk -v a=2 'NR>1 {print $a}' Tmin)
0   -23.339
0.254   -23.683
0   -24.301

To get columns from all 4 files we'll simply expand on this approach.

set our index ($i) to 1.

$ i=1
$ paste <(awk -v a=$i 'NR>1 {print $a}' Prec) <(awk -v a=$i 'NR>1 {print $a}' Tmin) <(awk -v a=$i 'NR>1{print $a}' Tmax) <(awk -v a=$i 'NR>1 {print $a}' wind)
0   -23.349 -17.087 0
0.254   -23.682 -20.082 1.778
0   -24.302 -20.48  1.652

set our index ($i) to 2.

$ i=2
$ paste <(awk -v a=$i 'NR>1 {print $a}' Prec) <(awk -v a=$i 'NR>1 {print $a}' Tmin) <(awk -v a=$i 'NR>1{print $a}' Tmax) <(awk -v a=$i 'NR>1 {print $a}' wind)
0   -23.339 -17.082 0
0.254   -23.683 -20.095 1.778
0   -24.301 -20.481 1.653

Putting it all together

So now let's incorporate the paste <(awk ..) <(awk ..) <(awk ..) <(awk ..) into the for loop.

$ for i in `seq 8`; do 
  echo "## $i ##"
  paste <(awk -v a=$i 'NR>1 {print $a}' Prec) <(awk -v a=$i 'NR>1 {print $a}' Tmin) <(awk -v a=$i 'NR>1{print $a}' Tmax) <(awk -v a=$i 'NR>1 {print $a}' wind)
done
## 1 ##
0   -23.349 -17.087 0
0.254   -23.682 -20.082 1.778
0   -24.302 -20.48  1.652
## 2 ##
0   -23.339 -17.082 0
0.254   -23.683 -20.095 1.778
0   -24.301 -20.481 1.653
## 3 ##
0   -23.327 -17.077 0
0.254   -23.685 -20.109 1.778
0   -24.3   -20.483 1.654
...

I've added an extra echo above so that in the output it's easier to see which column is being printed.

Writing everything to files

By adding this bit after the paste ... command, we can write the results out to the individual files as you specified.

paste ... | tee out$i.txt

The whole thing as a one liner:

$ for i in `seq 8`;do echo "## $i ##"; paste <(awk -v a=$i 'NR>1 {print $a}' Prec) <(awk -v a=$i 'NR>1 {print $a}' Tmin) <(awk -v a=$i 'NR>1{print $a}' Tmax) <(awk -v a=$i 'NR>1 {print $a}' wind) | tee out$i.txt;done

Which results in these files being written:

$ ll
total 48
-rw-rw-r-- 1 saml saml  71 Aug 21 23:17 out1.txt
-rw-rw-r-- 1 saml saml  72 Aug 21 23:17 out2.txt
-rw-rw-r-- 1 saml saml  70 Aug 21 23:17 out3.txt
-rw-rw-r-- 1 saml saml  72 Aug 21 23:17 out4.txt
-rw-rw-r-- 1 saml saml  71 Aug 21 23:17 out5.txt
-rw-rw-r-- 1 saml saml  71 Aug 21 23:17 out6.txt
-rw-rw-r-- 1 saml saml  70 Aug 21 23:17 out7.txt
-rw-rw-r-- 1 saml saml  71 Aug 21 23:17 out8.txt