README.qmd

---
title: "Sample of cppRouting with SfNetworks"
format: gfm
---

```{R, echo = FALSE}
#spsUtil::quiet(pacman::p_install("mapview", force = FALSE))
spsUtil::quiet(pacman::p_install("sf", force = FALSE))
spsUtil::quiet(pacman::p_install("sfnetworks", force = FALSE))
spsUtil::quiet(pacman::p_install("dplyr", force = FALSE))
```

Sample code to use sfnetworks with cppRouting

First load the functions.

```{R}
library(wrapr)

#Transform the sfnetworks network, in cppRouting format
sfnet2cppRouting <- modules::use("sfnet2cppRouting.R")

shortest_path <- modules::use("shortest_path.R")
min_distance <- modules::use("min_distance.R")
```

Then load the network and get the cppRouting one too.

```{R}
network <- "oldenburg_walking_network.geojson" %.>%
  #Read the file
  sf::st_read(., quiet = TRUE) %.>%
  #Only linestrings
  sf::st_cast(., "LINESTRING") %.>%
  #Set a column for the weight of the line as the distance
  dplyr::mutate(., weight = sf::st_length(.)) %.>%
  #Get the sfnetworks object
  sfnetworks::as_sfnetwork(., directed = FALSE)

weight <- "weight"

cppRouting_graph <- sfnet2cppRouting$sfnet2cppRouting(network, weight)
```

Set some random nodes to use:

```{R}
from <- c(1, 2, 3)
to <- c(5, 6, 7)
```

## Shortest Path Matrix:
```{R}
shortest_path$networks.shortest_path.node2node.cppRouting.matrix(network, cppRouting_graph, from, to)
```


## Shortest Path Pairs
```{R}
shortest_path$networks.shortest_path.node2node.cppRouting.pairs(network, cppRouting_graph, from, to)
```

## Min Distance Matrix
```{R}
min_distance$networks.min_distance.node2node.cppRouting.matrix(network, cppRouting_graph, from, to)
```

## Min Distance Paris
```{R}
min_distance$networks.min_distance.node2node.cppRouting.pairs(network, cppRouting_graph, from, to)
```

## Notes

All returns are a dataframe with "from", "to" columns with the nodes, the last column depends if is distance or shortestpath.

- distance: Use the column distance
- shortestpath: Use the "path" column, is a geom column