Time of adoption matrix
Description
Creates two matrices recording times of adoption of the innovation. One matrix records the time period of adoption for each node with zeros elsewhere. The second records the cumulative time of adoption such that there are ones for the time of adoption and every time period thereafter.
Usage
1 
Arguments
obj 
Either an integer vector of size n containing time of adoption of the innovation,
or a 
labels 
Character vector of size n. Labels (ids) of the vertices. 
t0 
Integer scalar. Sets the lower bound of the time window (e.g. 1955). 
t1 
Integer scalar. Sets the upper bound of the time window (e.g. 2000). 
Details
In order to be able to work with time ranges other than 1,..., T
the function receives as input the boundary labels of the time windows through
the variables t0
and t
. While by default the function assumes that
the the boundaries are given by the range of the times
vector, the user
can set a personalized time range exceeding the one given by the times
vector. For instance, times of adoption may range between 2001 and 2005 but the
actual data, the network, is observed between 2000 and 2005 (so there is not
left censoring in the data), hence, the user could write:
1  adopmats < toa_mat(times, t0=2000, t1=2005)

That way the resulting cumadopt
and adopt
matrices would have
2005  2000 + 1 = 6 columns instead of 2005  2001 + 1 = 5 columns, with the
first column of the two matrices containing only zeros (as the first adoption
happend after the year 2000).
Value
A list of two n x T

has 1's for all years in which a node indicates having the innovation. 

has 1's only for the year of adoption and 0 for the rest. 
Author(s)
George G. Vega Yon, Stephanie R. Dyal, Timothy B. Hayes & Thomas W. Valente
Examples
1 2 3 4 5 6 7 