---
title: "Transport routing with stplanr"
output: rmarkdown::html_vignette
vignette: >
  %\VignetteIndexEntry{stplanr vignette 3: routing}
  %\VignetteEngine{knitr::rmarkdown}
  %\VignetteEncoding{UTF-8}
---

```{r, include = FALSE}
knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>"
)
```

```{r setup}
library(stplanr)
```

## This vignette is work in progress - watch this space!


```{r, echo=FALSE, eval=FALSE}
# upload roads data
if(!file.exists("roads_iow.Rds")) {
  download.file("https://github.com/ropensci/stplanr/releases/download/0.3.1/roads_iow.Rds", "roads_iow.Rds")
}
roads_iow = readRDS("roads_iow.Rds")
sf::write_sf(roads_iow, "roads_iow.geojson")
piggyback::pb_upload("roads_iow.geojson")
```

```{r, eval=FALSE}
roads_iow = sf::read_sf("https://github.com/ropensci/stplanr/releases/download/0.3.1/roads_iow.geojson")
```

# OSRM

Routing services such as OpenStreetMap Routing Machine (OSRM) require an input network, usually from OSM.

We will use the `osrm` package:

```{r}
library(osrm)
```

To get OSM data for the Isle of Wight, for example, you can run the following commands:

```{r, eval=FALSE}
remotes::install_github("itsleeds/geofabrik")
library(geofabrik)
iow = get_geofabrik(name = "Isle of Wight")
f = gf_filename("Isle of Wight")
file.copy(f, "iow.pbf")
options(osrm.server = "http://0.0.0.0:5000/", osrm.profile = "driving")
```


```{r, echo=FALSE, eval=FALSE}
if(!file.exists("iow.pbf"))
  download.file("http://download.geofabrik.de/europe/great-britain/england/isle-of-wight-latest.osm.pbf", "iow.pbf")
```

Then in bash run the following commands to make the [OSRM docker image](https://hub.docker.com/r/osrm/osrm-backend/) work for you.

```{r, engine='bash', eval=FALSE}
docker run -t -v "${PWD}:/data" osrm/osrm-backend osrm-extract -p /opt/car.lua /data/iow.pbf
docker run -t -v "${PWD}:/data" osrm/osrm-backend osrm-partition /data/iow.osrm
docker run -t -v "${PWD}:/data" osrm/osrm-backend osrm-customize /data/iow.osrm
docker run -t -i -p 5000:5000 -v "${PWD}:/data" osrm/osrm-backend osrm-routed --algorithm mld /data/iow.osrm
curl "http://127.0.0.1:5000/route/v1/driving/13.388860,52.517037;13.385983,52.496891?steps=true"
```

Now we can do routing in R!

On a single route:

```{r}
l = pct::wight_lines_30
p = line2points(l)
r = osrm::osrmRoute(src = p[1, ], dst = p[2, ], returnclass = "sf", overview = "full")
plot(r)
```

And to find many routes via the `route()` function, resulting in something like the figure below.

```{r, eval=FALSE}
routes_osrm = route(l = l, route_fun = osrmRoute, returnclass = "sf", overview = "full")
rnet_osrm = overline(routes_osrm, attrib = "bicycle")
mapview::mapview(rnet_osrm, lwd = rnet_osrm$bicycle / 10)
```

```{r, eval=FALSE, echo=FALSE}
system.time({
  routes_osrm = route(l = l, route_fun = osrmRoute, returnclass = "sf", overview = "full")
})
30 / 0.9 # around 30 routes per second
saveRDS(routes_osrm, "routes_osrm.Rds")
piggyback::pb_upload("routes_osrm.Rds")
```


```{r, echo=FALSE}
knitr::include_graphics("https://user-images.githubusercontent.com/1825120/86858225-2970df80-c0b8-11ea-8394-07f98f1c8e8a.png")
```

```{r, eval=FALSE}
# tidy up
f = list.files(pattern = "iow")
unlink(x = f, recursive = TRUE)
```

Shut down the docker container.


```{r, eval=FALSE, engine='zsh'}
docker ps
docker stop stupefied_hopper
```


