B3_osm_mainapi.R

#' ---
#' title: "B3 Die OSM main api"
#' author: "Jan-Philipp Kolb"
#' date: "23 Oktober 2018"
#' output:
#'   beamer_presentation: 
#'     colortheme: beaver
#'     fonttheme: structurebold
#'     highlight: espresso
#'     incremental: yes
#'     keep_tex: yes
#'     theme: CambridgeUS
#'   slidy_presentation: 
#'     keep_md: yes
#' ---
#' 
## ----setup_mainosmapi, include=FALSE-------------------------------------
knitr::opts_chunk$set(echo = TRUE)
library(knitr)
Ex <- T

#' 
#' 
#' ## [OSM Ausschnitte herunterladen](http://www.openstreetmap.org/export)
#' 
#' <www.openstreetmap.org/export>
#' 
#' ![osm export](figure/openstreetmap_export-1024x505.png)
#' 
#' 
#' ## Das R-Paket `XML` - Gaston Sanchez
#' 
## ------------------------------------------------------------------------
library("XML")

#' 
#' ### Gaston Sanchez - Dataflow
#' 
#' ![](figure/GastonSanchez2.png)
#' 
#' Seine Arbeit sieht man [**hier**](http://gastonsanchez.com/).
#' 
#' 
#' ## [Das Arbeiten mit XML Daten](https://github.com/gastonstat/tutorial-R-web-data/blob/master/04-parsing-xml/04-parsing-xml.pdf)
#' 
#' ![Gaston Sanchez - Webdaten bekommen](figure/GastonSanchez3.PNG)
#' 
#' 
#' ## Funktionen im XML Paket
#' 
## ----echo=F,eval=T-------------------------------------------------------
names <- c("xmlName()","name of the node","xmlSize()","number of subnodes","xmlAttrs()","named character vector of all attributes","xmlGetAttr()","value of a single attribute","xmlValue()","contents of a leaf node","xmlParent()","name of parent node","xmlAncestors()","name of ancestor nodes","getSibling()","siblings to the right or to the left","xmlNamespace()","the namespace (if there’s one)")
tab <- data.frame(t(array(names,dim=c(2,length(names)/2))))
colnames(tab) <- c("Function","Description")
kable(tab)

#' 
#' 
#' ## [Einzelne Objekte finden](http://www.openstreetmap.org/export)
#' 
#' <www.openstreetmap.org/export>
#' 
#' ![osm export](figure/admgrBer.PNG)
#' 
#' 
#' ## Beispiel: administrative Grenzen Berlin
#' 
#' [Administrative Grenzen für Deutschland](http://wiki.openstreetmap.org/wiki/DE:Grenze#Bundesl.C3.A4ndergrenze_-_admin_level.3D4)
#' 
## ----echo=T--------------------------------------------------------------
url <- "https://api.openstreetmap.org/api/0.6/relation/62422"

#' 
## ----echo=F,eval=F-------------------------------------------------------
##  library(xml2)
##  BE <- xml2::read_xml.raw(url)

#' 
#' 
## ----eval=F--------------------------------------------------------------
## BE <- xmlParse(url)

#' 
## ------------------------------------------------------------------------
BE <- xmlParse("../data/62422.xml")

#' 
#' 
#' ![Administrative Grenzen  Berlin](figure/ExampleAdmBE.PNG)
#' 
#' ## Das XML analysieren
#' 
#' - [Tobi Bosede - Working with XML Data in R](http://www.informit.com/articles/article.aspx?p=2215520)
#' 
## ----eval=Ex-------------------------------------------------------------
xmltop = xmlRoot(BE)
class(xmltop)
xmlSize(xmltop)
xmlSize(xmltop[[1]])

#' 
#' 
#' ## Nutzung von Xpath
#' 
#' > [Xpath](https://de.wikipedia.org/wiki/XPath), the XML Path Language, is a query language for selecting nodes from an XML document. 
#' 
## ----eval=Ex-------------------------------------------------------------
xpathApply(BE,"//tag[@k = 'population']")

#' 
#' 
#' ## Quelle für die Bevölkerungsgröße
#' 
## ------------------------------------------------------------------------
xpathApply(BE,"//tag[@k = 'source:population']")

#' 
#' -[**Statistik Berlin Brandenburg**](https://www.statistik-berlin-brandenburg.de/datenbank/inhalt-datenbank.asp)
#' 
#' ## Etwas überraschend: 
#' 
## ------------------------------------------------------------------------
xpathApply(BE,"//tag[@k = 'name:ta']")

#' 
#' ![](figure/OSMBerta.png)
#' 
#' ## Geographische Region
#' 
## ------------------------------------------------------------------------
region <- xpathApply(BE,
  "//tag[@k = 'geographical_region']")
# regular expressions
region[[1]]

#' 
#' ```
#' <tag k="geographical_region" 
#'   v="Barnim;Berliner Urstromtal;
#'   Teltow;Nauener Platte"/>
#' ```
#' 
#' ## Landkreis
#' 
#' ![Barnim](figure/Barnim.png)
#' 
#' 
#' ## Weiteres Beispiel
#' 
## ----eval=F--------------------------------------------------------------
## url2<-"http://api.openstreetmap.org/api/0.6/node/25113879"
## obj2<-xmlParse(url2)
## obj_amenity<-xpathApply(obj2,"//tag[@k = 'amenity']")[[1]]
## obj_amenity

#' 
## ----echo=F--------------------------------------------------------------
obj2<-xmlParse("../data/25113879.xml")
obj_amenity<-xpathApply(obj2,"//tag[@k = 'amenity']")[[1]]
obj_amenity

#' 
#' 
#' 
#' ## Wikipedia Artikel
#' 
## ------------------------------------------------------------------------
xpathApply(obj2,"//tag[@k = 'wikipedia']")[[1]]

#' 
## ----eval=F--------------------------------------------------------------
## xpathApply(obj2,"//tag[@k = 'wheelchair']")[[1]]

#' 
## ----eval=F--------------------------------------------------------------
## xpathApply(obj2,"//tag[@k = 'name']")[[1]]

#' 
#' 
#' ## Das C und das A
#' 
## ----eval=F--------------------------------------------------------------
## url3<-"http://api.openstreetmap.org/api/0.6/node/303550876"
## obj3 <- xmlParse(url3)
## xpathApply(obj3,"//tag[@k = 'opening_hours']")[[1]]

#' 
## ----echo=F--------------------------------------------------------------
obj3 <- xmlParse("../data/303550876.xml")
xpathApply(obj3,"//tag[@k = 'opening_hours']")[[1]]

#' 
#' 
#' ## Hin und weg
#' 
## ----eval=F--------------------------------------------------------------
## url4<-"http://api.openstreetmap.org/api/0.6/node/25439439"
## obj4 <- xmlParse(url4)
## xpathApply(obj4,"//tag[@k = 'railway:station_category']")[[1]]

#' 
## ----echo=F--------------------------------------------------------------
obj4 <- xmlParse("../data/25439439.xml")
xpathApply(obj4,"//tag[@k = 'railway:station_category']")[[1]]

#' 
#' 
#' 
#' - [**Wikipedia Artikel Bahnhofskategorien**](https://de.wikipedia.org/wiki/Bahnhofskategorie)
#' 
#' ![](figure/Bahnhofskategorien.PNG)
#' 
#' ## Exkurs: Bahnhofskategorien
#' 
#' - [**rvest: Easily Harvest (Scrape) Web Pages**](https://cran.r-project.org/web/packages/rvest/index.html)
#' 
## ------------------------------------------------------------------------
library(rvest)
bhfkat<-read_html(
  "https://de.wikipedia.org/wiki/Bahnhofskategorie")
df_html_bhfkat<-html_table(
  html_nodes(bhfkat, "table")[[2]],fill = TRUE)

#' 
#' ## Bahnhofskategorien Übersicht
#' 
## ----echo=F--------------------------------------------------------------
library(knitr)
kable(df_html_bhfkat)

#' 
#' ## Nur fliegen ist schöner
#' 
## ----eval=F--------------------------------------------------------------
## url5<-"http://api.openstreetmap.org/api/0.6/way/162149882"
## obj5<-xmlParse(url5)
## xpathApply(obj5,"//tag[@k = 'name']")[[1]]

#' 
## ----echo=F--------------------------------------------------------------
obj5<-xmlParse("../data/162149882.xml")
xpathApply(obj5,"//tag[@k = 'name']")[[1]]

#' 
#' 
## ------------------------------------------------------------------------
xpathApply(obj5,"//tag[@k = 'website']")[[1]]

#' 
#' 
## ------------------------------------------------------------------------
xpathApply(obj5,"//tag[@k = 'iata']")[[1]]

#' 
#' ## Das Paket `osmar` benutzen
#' 
## ------------------------------------------------------------------------
library("osmar")
node_ <- xmlParse("../data/162149882.xml")
node_osmar <- as_osmar(node_)
node_osmar

#' 
#' ## [Drei Typen von Vektorobjekten](https://www.earthdatascience.org/courses/earth-analytics/spatial-data-r/intro-vector-data-r/)
#' 
#' <!--
#' https://www.earthdatascience.org/courses/earth-analytics/spatial-data-r/intro-vector-data-r/
#' -->
#' 
#' ![](figure/points-lines-polygons-vector-data-types.png)
#' 
#' ## Die Ausdehnung
#' 
#' ![](figure/spatial-extent.png)
#' 
#' 
#' ## [Import mit dem Paket `sf`](https://cran.r-project.org/web/packages/sf/vignettes/sf2.html)
#' 
#' 
## ----eval=T--------------------------------------------------------------
library(sf)

#' 
#' - Mit dem Befehl `st_layers` kann man sehen, welche Layer verfügbar sind:
#' 
## ------------------------------------------------------------------------
st_layers("../data/Amsterdam_highway_primary.osm")

#' 
#' ## Import von Layer `lines`
#' 
## ------------------------------------------------------------------------
dat <- st_read("../data/Amsterdam_highway_primary.osm",
               "lines")

#' 
#' ## Den Layer plotten
#' 
## ------------------------------------------------------------------------
plot(dat$geometry)

#' 
#' 
#' ## Import von Layer `points`
#' 
## ------------------------------------------------------------------------
datp <- st_read("../data/Amsterdam_highway_primary.osm",
                "points")

#' 
#' ## Den Layer `points` plotten
#' 
## ------------------------------------------------------------------------
plot(dat$geometry,pch=20,col=rgb(0,0,1,.1))

#' 
#' 
#' ## Mit einem anderen Paket plotten
#' 
## ------------------------------------------------------------------------
library(tmap)
qtm(dat$geometry)

#' 
#' ## 
#' 
## ------------------------------------------------------------------------
st_layers("../data/ams_centraal.osm")

#' 
## ------------------------------------------------------------------------
datm <- st_read("../data/ams_centraal.osm","multipolygons")
sp::plot(datm$geometry)

#' 
#' 
#' ## Mehr Beispiele, wie man mit XML Daten umgeht:
#' 
#' - Deborah Nolan - [**Extracting data from XML**](http://www.stat.berkeley.edu/~statcur/Workshop2/Presentations/XML.pdf)
#' - Duncan Temple Lang - [**A Short Introduction to the XML package for R**](http://www.omegahat.net/RSXML/shortIntro.pdf)
#' 
#' 
#' ### Noch mehr Informationen
#' 
#' - [**Web Daten manipulieren**](http://www.di.fc.ul.pt/~jpn/r/web/index.html#parsing-xml)
#' 
#' - [**Tutorial zu xquery**](http://www.w3schools.com/xml/xquery_intro.asp)
#' 
#' - [**R und das Web (für Anfänger), Teil II: XML und R**](http://giventhedata.blogspot.de/2012/06/r-and-web-for-beginners-part-ii-xml-in.html)
#' 
#' - Gaston Sanchez - [**String Manipulation**](http://gastonsanchez.com/Handling_and_Processing_Strings_in_R.pdf)
#' 
#' - [**Nutzung, Vor- und Nachteile OSM**](https://www.e-education.psu.edu/geog585/node/738)
#' 
#' - [**Forschungsprojekte im Zusammenhang mit OpenStreetMap**](http://wiki.openstreetmap.org/wiki/Research)
#' 
#' ## Referenzen
#' 
## ------------------------------------------------------------------------
citation("XML")

#' 
#' ## Das neuere Paket
#' 
## ------------------------------------------------------------------------
citation("xml2")

#' 
#' 
#' <!--
#' https://cran.r-project.org/web/packages/XML2R/XML2R.pdf
#' -->
#' 
#' 
## ----eval=FALSE, include=FALSE-------------------------------------------
## library(sf)
## dat <- st_read("../data/162149882.xml")
## dat <- st_read("../data/Amsterdam_highway_primary.osm")

#'