[R] Visualization of people's interactions by participation to parties

[Voxcoelestis]

Dear all,

I have a long list of parties and participants over many years and want 
to extract network relations between people to identify groups of 
friends. My list looks like this:

Party 1; date party 1; first name 1 last name 1; first name 2 last name 
2; first name 3 last name 3;
Party 2; date party 2; first name 1 last name 1; first name 3 last name 
3; first name 4 last name 4;
Party 3; date party 3; first name 3 last name 3; first name 5 last name 5;
Party 4; date party 4; first name 2 last name 2; first name 6 last name 
6; first name 3 last name 3; first name 1 last name 1;
Party 5; date party 5; first name 5 last name 5; first name 4 last name 4;
....

Obviously the amount and the order of names is not regular. The list is 
far too long to count co-appearances for each person-person combination 
by hand.

What I would like to do is first of all create a network with individual 
persons as nodes and the co-appearances as edges and the number of 
co-appearances as strenght of interactions clustering closesly related 
people.

In a second step it would be beneficial to extract information on the 
durability of these interactions by including the time difference 
between first and last interaction.

Do you have any ideas or hints how to approach this problem?

Thank you so much,

Hendrik