How to increment a column in AWK

[hailholyghost]

Hi,

I want to make a graph of the Karplus function

f($1) = 15.3*(cos((180/$pi)*$1+120))**2-6.2*cos((180/$pi)*$1+120)+1.5

I want to make the text file with AWK, as a learning experience to get away from Libre Office.

I want it to look like

0 f(0)
1 f(1)
2 f(2)
3 f(3)

etc. so I can graph it easily with Grace. I've found numerous reference to this working from another file but never creating one from awk.

I thought of something like (pca is a perl math script, and this doesn't work)


awk 'BEGIN {t=0} {print $1, pca '15.3*(cos((180/3.14)*$1+120))**2-6.2*cos((180/3.14)*$1+120)+1.5', t++}'

but I can't find information about how far to take the incrementation.

Your help is greatly appreciated!
-Dave:D

[geirha]

Use a for-loop in the BEGIN block.

awk '
BEGIN {
for (t=0;t<100;t++) {
print t, 15.3*...;
}
}'


What you're doing now is doing the calculation of the first field of each line of input, but it doesn't sound like you want that.

[hailholyghost]

Thank you very much geirha! It worked beautifully!