bash script to convert a file

habdulsalam · 02-28-2016, 03:22 AM

I have a file (totalenergy.dat) containing the lattice constants and total energies per atom and i want to convert it to to a file (cohesive.dat) containing atomic volumes and cohesive energies by the script. How do i write the script?
where the cohesive energy = (total energy per unit cell/number of atoms)-energy per atom

grail · 02-28-2016, 05:33 AM

Show some example data both what you start with and your desired results.

Then show us what you have tried an where you are stuck?

syg00 · 02-28-2016, 05:43 AM

My thinking was:
who is getting paid to produce the results here ?.

determine your constants, determine your variables, do the maths.
Don't expect us to do it for you.

aragorn2101 · 02-29-2016, 01:54 AM

Hello there,

To be frank with you, you could have formulated your question otherwise; you could have placed a sample of your data file here and asked about the tools in a Linux system which could help you solve your problem.

Anyway, I think Bash is not best suited for your problem, because, even if you can do arithmetics in Bash, it is highly dependent on other utilities for doing the math as Bash is not intended for that in the first place.

What other languages do you know? C, Python, FORTRAN?

habdulsalam · 02-29-2016, 03:17 AM

Hello there
First of all nobody is getting paid, the arithemric is not the problem here, I need the FHI-aims bash script so that I will do all my work using FHI-aims.

grail · 02-29-2016, 03:45 AM

So now we have the formula and the original input ... good start

What does the desired output look like and as asked above, what if any languages do you know?

Not sure if anyone else does, but I am also unfamiliar with what 'FHI-aims' is?? (it may not be important)

I will advise that whilst you could do this in bash and use bc, I would probably pick a language that can perform decimal arithmetic itself.
Suggestions would be something like :- awk, perl, python, ruby,...

John VV · 02-29-2016, 07:21 PM

NASA/JPL released a python based toolkit
"data Productivity ToolKit"
https://oodt.jpl.nasa.gov/wiki/display/OPENSOURCE/Home

hosted on SF
https://sourceforge.net/projects/dptoolkit/

it might help

BW-userx · 02-29-2016, 07:51 PM

Quote:

Originally Posted by grail

So now we have the formula and the original input ... good start

What does the desired output look like and as asked above, what if any languages do you know?

Not sure if anyone else does, but I am also unfamiliar with what 'FHI-aims' is?? (it may not be important)

I will advise that whilst you could do this in bash and use bc, I would probably pick a language that can perform decimal arithmetic itself.
Suggestions would be something like :- awk, perl, python, ruby,...

I don't even think bash does floating point, if I remember correctly... especially with E left overs, but I could be wrong.

OP would be better off trying @John VV Idea post #7 unless pascal might work for OP,
Lazarus and open pascal got graphs too. make it look all fancy like even.

Open Pascal is an easy programming language to learn. IMO and lots others too.

. As noted by others, bash does not support floating point arithmetic.

habdulsalam · 02-29-2016, 11:42 PM

Thanks, I was able to solve the problem using awk

grail · 03-01-2016, 09:08 AM

So please post your solution for others to learn from your experience

Also, please mark as SOLVED now you have a solution.

BW-userx · 03-01-2016, 09:23 AM

he said Please....