I have a data frame that contains the monetary transactions among individuals. The transactions can be two-way, i.e. A can transfer money to B and B can also transfer money to A. The structure of the data frame looks like below:
From To Amount
A B $100
A C $40
A D $30
B A $25
B C $70
C A $190
C D $110
I want to summarize the total amount of transactions among each pair of individuals who have transactions with each other and the results should be something like:
Individual_1 Individual_2 Sum
A B $125
A C $230
A D $30
B C $70
C D $110
I tried to utilize the grouping feature of the package dplyr but I think it does not apply to my case.