[R] family

[Val]

Hi all,
I am reading a huge data set(12M rows) that contains family information,
Offspring, Parent1 and Parent2

Parent1 and parent2 should be in the first column as an offspring
before their offspring information. Their parent information (parent1
and parent2) should be  set to zero, if unknown.  Also the first
column should be unique.


Here is my sample data  set  and desired output.


fam <- read.table(textConnection(" offspring  Parent1 Parent2
Smith Alex1  Alexa
Carla Alex1     0
Jacky Smith   Abbot
Jack  0       Jacky
Almo  Jack    Carla
 "),header = TRUE)



desired output.
Offspring Parent1 Parent2
Alex1      0        0
Alexa      0        0
Abbot      0        0
Smith    Alex1  Alexa
Carla    Alex1      0
Jacky    Smith   Abbot
Jack       0     Jacky
Almo     Jack    Carla

Thank you.