Question

I want to plot email from and to in world. For example, I received the following number of emails from the following countries and I live in USA.

recievedcountry <- c("India", "China", "France", "Chile", "Australia", "Chad",
                    "Nepal", "Burma")
rfrequency <- c(12, 20, 5, 2, 12, 1, 3, 2) # frequency of emails 
sendcountry <- c("Canda", "USA", "France", "India", "China", "Japan")
sfrequency <- c(14, 108, 12, 15, 18, 4)

This what I tried but I do not know how to conect with lines:

require(fields)
world(xlim=c(-90,90),ylim=c(-180,180), xaxt = "s", yaxt = "s")
grid()

The following is my hypothesize model:

Answer 1

This has been thought before. Look at this blog entry, it describes how to construct such a map very carefully.

http://flowingdata.com/2011/05/11/how-to-map-connections-with-great-circles/