mymatrix is an igraph object (weighted adjacency matrix):
> summary(mymatrix)
IGRAPH 14317c4 UNW- 810 8761 --
+ attr: name (v/c), year (v/n), bad (v/n), new (v/n), weight (e/n)
One of the node attributes is year:
> summary(V(mymatrix)$year)
Min. 1st Qu. Median Mean 3rd Qu. Max.
1990 2011 2014 2013 2017 2019
newmatrix is an igraph object that only includes nodes associated with a given year. If the value of year is greater than 2013, I want to remove the node from both the row and column of the matrix prior to graphing and analysis.
I tried to use filter() in the dplyr package and get the following error:
> newmatrix<-filter(mymatrix, V(mymatrix)$year<2013)
Error in UseMethod("filter_") :
no applicable method for 'filter_' applied to an object of class "igraph"
One work-around is modifying the data I used to produce the adjacency matrix in the first place. But I wanted to know if there was a way to filter igraph objects by node attributes that I haven't found in the documentation.
Looks like
delete_vertices(mymatrix, V(mymatrix)$year >= 2013)
should give the expected graph.