Read the number of columns using awk/sed - bash

Question

I have the following test file
Kmax Event File - Text Format
1 4 1000
65 4121 9426 12312
56 4118 8882 12307
1273 4188 8217 12309
1291 4204 8233 12308
1329 4170 8225 12303
1341 4135 8207 12306
63 4108 8904 12300
60 4106 8897 12307
731 4108 8192 12306
...
ÿÿÿÿÿÿÿÿ
In this file I want to delete the first two lines and apply some mathematical calculations. For instance each column i will be $i-(i-1)*number. A script that does this is the following
#!/bin/bash
if test $1 ; then
if [ -f $1.evnt ] ; then
rm -f $1.dat
sed -n '2p' $1.evnt | (read v1 v2 v3
for filename in $1*.evnt ; do
echo -e "Processing file $filename"
sed '$d' < $filename > $1_tmp
sed -i '/Kmax/d' $1_tmp
sed -i '/^'"$v1"' '"$v2"' /d' $1_tmp
cat $1_tmp >> $1.dat
done
v3=`wc -l $1.dat | awk '{print $1}' `
echo -e "$v1 $v2 $v3" > .$1.dat
rm -f $1_tmp)
else
echo -e "\a!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
echo -e " Event file $1.evnt doesn't exist !!!!!!"
echo -e "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
fi
else
echo -e "\a!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
echo -e "!!!!! Give name for event files !!!!!"
echo -e "!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
fi
awk '{print $1, $2-4096, $3-(2*4096), $4-(3*4096)}' $1.dat >$1_Processed.dat
rm -f $1.dat
exit 0
The file won't always have 4 columns. Is there a way to read the number of columns, print this number and apply those calculations?
EDIT The idea is to have an input file (*.evnt), convert it to *.dat or any other ascii file(it doesn't matter really) which will only include the number in columns and then apply the calculation $i=$i-(i-1)*number. In addition it will keep the number of columns in a variable, that will be called in another program. For instance in the above file, number=4096 and a sample output file is the following
65 25 1234 24
56 22 690 19
1273 92 25 21
1291 108 41 20
1329 74 33 15
1341 39 15 18
63 12 712 12
60 10 705 19
731 12 0 18
while in the console I will get the message There are 4 detectors.
Finally a new file_processed.dat will be produced, where file is the initial name of awk's input file.
The way it should be executed is the following
./myscript <filename>
where <filename> is the name without the format. For instance, the files will have the format filename.evnt so it should be executed using
./myscript filename

Answer 1

Let's start with this to see if it's close to what you're trying to do:
$ numdet=$( awk -v num=4096 '
NR>2 && NF>1 {
out = FILENAME "_processed.dat"
for (i=1;i<=NF;i++) {
$i = $i-(i-1)*num
}
nf = NF
print > out
}
END {
printf "There are %d detectors\n", nf | "cat>&2"
print nf
}
' file )
There are 4 detectors
$ cat file_processed.dat
65 25 1234 24
56 22 690 19
1273 92 25 21
1291 108 41 20
1329 74 33 15
1341 39 15 18
63 12 712 12
60 10 705 19
731 12 0 18
$ echo "$numdet"
4
Is that it?

Answer 2

Using awk
awk 'NR<=2{next}{for (i=1;i<=NF;i++) $i=$i-(i-1)*4096}1' file