trav_out_node {DiagrammeR} | R Documentation |
From a graph object of class
dgr_graph
with an active selection of
edges move opposite to the edge direction to
connected nodes, replacing the current edge selection
with those nodes traversed to. An optional filter by
node attribute can limit the set of nodes traversed
to.
trav_out_node(graph, conditions = NULL, copy_attrs_from = NULL, copy_attrs_as = NULL, agg = "sum")
graph |
a graph object of class
|
conditions |
an option to use filtering conditions for the traversal. |
copy_attrs_from |
providing an edge attribute name will copy those edge attribute values to the traversed nodes. If the edge attribute already exists, the values will be merged to the traversed nodes; otherwise, a new node attribute will be created. |
copy_attrs_as |
if an edge attribute name
is provided in |
agg |
if an edge attribute is provided
to |
a graph object of class dgr_graph
.
# Set a seed set.seed(23) # Create a simple graph graph <- create_graph() %>% add_n_nodes( n = 2, type = "a", label = c("asd", "iekd")) %>% add_n_nodes( n = 3, type = "b", label = c("idj", "edl", "ohd")) %>% add_edges_w_string( edges = "1->2 1->3 2->4 2->5 3->5", rel = c(NA, "A", "B", "C", "D")) # Create a data frame with node ID values # representing the graph edges (with `from` # and `to` columns), and, a set of numeric values df_edges <- data.frame( from = c(1, 1, 2, 2, 3), to = c(2, 3, 4, 5, 5), values = round(rnorm(5, 5), 2)) # Create a data frame with node ID values # representing the graph nodes (with the `id` # columns), and, a set of numeric values df_nodes <- data.frame( id = 1:5, values = round(rnorm(5, 7), 2)) # Join the data frame to the graph's internal # edge data frame (edf) graph <- graph %>% join_edge_attrs(df = df_edges) %>% join_node_attrs(df = df_nodes) # Show the graph's internal node data frame graph %>% get_node_df() # Show the graph's internal edge data frame graph %>% get_edge_df() # Perform a simple traversal from the # edge `1`->`3` to the attached node # in the direction of the edge; here, no # conditions are placed on the nodes # traversed to graph %>% select_edges( from = 1, to = 3) %>% trav_out_node() %>% get_selection() # Traverse from edges `2`->`5` and # `3`->`5` to the attached node along # the direction of the edge; here, the # traversals lead to different nodes graph %>% select_edges( from = 2, to = 5) %>% select_edges( from = 3, to = 5) %>% trav_out_node() %>% get_selection() # Traverse from the edge `1`->`3` # to the attached node where the edge # is outgoing, this time filtering # numeric values greater than `7.0` for # the `values` node attribute graph %>% select_edges( from = 1, to = 3) %>% trav_out_node( conditions = values > 7.0) %>% get_selection() # Traverse from the edge `1`->`3` # to the attached node where the edge # is outgoing, this time filtering # numeric values less than `7.0` for # the `values` node attribute (the # condition is not met so the original # selection of edge `1`->`3` remains) graph %>% select_edges( from = 1, to = 3) %>% trav_out_node( conditions = values < 7.0) %>% get_selection() # Traverse from the edge `1`->`2` # to node `2`, using multiple conditions graph %>% select_edges( from = 1, to = 2) %>% trav_out_node( conditions = grepl(".*d$", label) | values < 6.0) %>% get_selection() # Create another simple graph to demonstrate # copying of edge attribute values to traversed # nodes graph <- create_graph() %>% add_node() %>% select_nodes() %>% add_n_nodes_ws( n = 2, direction = "from") %>% clear_selection() %>% select_nodes_by_id(nodes = 2) %>% set_node_attrs_ws( node_attr = value, value = 8) %>% clear_selection() %>% select_edges_by_edge_id(edges = 1) %>% set_edge_attrs_ws( edge_attr = value, value = 5) %>% clear_selection() %>% select_edges_by_edge_id(edges = 2) %>% set_edge_attrs_ws( edge_attr = value, value = 5) %>% clear_selection() %>% select_edges() # Show the graph's internal edge data frame graph %>% get_edge_df() # Show the graph's internal node data frame graph %>% get_node_df() # Perform a traversal from the edges to # the central node (`1`) while also applying # the edge attribute `value` to the node (in # this case summing the `value` of 5 from # both edges before adding as a node attribute) graph <- graph %>% trav_out_node( copy_attrs_from = value, agg = "sum") # Show the graph's internal node data frame # after this change graph %>% get_node_df()