Grouping Data

[Pgs]

Hi

I have a txt file as per example below......

My txt file or data frame

col1, col2,col3,col4

A,    1,      4,      2

A ,   1,      8,      4

A ,   2,      6,      3

A     2,      9,      3

B,    1,      8,      4

B,    1,      4,      2

So,  I now want to apply a function to columns 3&4  but Group by columns 1&2

myfunction = minimum $ zipWith (/) col3 col4

This is where I am stuck!

I want to apply the function "myfunction" to cols 3& 4 and then get the minimum number per group set of columns 1&2

1st pass

col1, col2,col3,col4

A,    1,      2

A ,   1,      2

A ,   2,      2

A     2,      3

B,    1,      2

B,    1,      2

Below is the result set I'm looking for

2nd pass

A, 1, 2

A, 2, 2

B, 1, 2

Regards