# map_local

##### Map a function over a graph representing the neighborhood of each node

This function extracts the neighborhood of each node as a graph and maps over
each of these neighborhood graphs. Conceptually it is similar to
`igraph::local_scan()`

, but it borrows the type safe versions available in
`map_bfs()`

and `map_dfs()`

.

##### Usage

`map_local(order = 1, mode = "all", mindist = 0, .f, ...)`map_local_lgl(order = 1, mode = "all", mindist = 0, .f, ...)

map_local_chr(order = 1, mode = "all", mindist = 0, .f, ...)

map_local_int(order = 1, mode = "all", mindist = 0, .f, ...)

map_local_dbl(order = 1, mode = "all", mindist = 0, .f, ...)

##### Arguments

- order
Integer giving the order of the neighborhood.

- mode
Character constant, it specifies how to use the direction of the edges if a directed graph is analyzed. For ‘out’ only the outgoing edges are followed, so all vertices reachable from the source vertex in at most

`order`

steps are counted. For ‘"in"’ all vertices from which the source vertex is reachable in at most`order`

steps are counted. ‘"all"’ ignores the direction of the edges. This argument is ignored for undirected graphs.- mindist
The minimum distance to include the vertex in the result.

- .f
A function to map over all nodes. See Details

- ...
Additional parameters to pass to

`.f`

##### Details

The function provided to `.f`

will be called with the following arguments in
addition to those supplied through `...`

:

`neighborhood`

: The neighborhood graph of the node`graph`

: The full`tbl_graph`

object`node`

: The index of the node currently mapped over

##### Value

`map_local()`

returns a list of the same length as the number of
nodes in the graph, in the order matching the node order in the graph.
`map_local_*()`

tries to coerce its result into a vector of the classes
`logical`

(`map_local_lgl`

), `character`

(`map_local_chr`

), `integer`

(`map_local_int`

), or `double`

(`map_local_dbl`

). These functions will throw
an error if they are unsuccesful, so they are type safe.

##### Examples

```
# NOT RUN {
# Smooth out values over a neighborhood
create_notable('meredith') %>%
mutate(value = rpois(graph_order(), 5)) %>%
mutate(value_smooth = map_local_dbl(order = 2, .f = function(neighborhood, ...) {
mean(as_tibble(neighborhood, active = 'nodes')$value)
}))
# }
```

*Documentation reproduced from package tidygraph, version 1.1.2, License: MIT + file LICENSE*