I have a csv file file1. I'm reading from it and modifying certain columns in it. If I use write.table(modifieddataframe, file1,..), instead of modifying the existing data, new data is getting added. How do I modify already present data.
Example:
Input
c1 c2 c3
.. b1 ..
.. b2 ..
.. b3 ..
Output
c1 c2 c3
.. a1 ..
.. a2 ..
.. a3 ..