Wikisym 2012 Demo: Difference between revisions

Revision as of 11:21, 21 August 2012

Polygons on dynamic Google Maps

This example plots municipalities of Finland on Google Maps using data from National Land Survey of Finland.


library(OpasnetBaseUtils)
library(sorvi)
library(rgdal)

# Get the shape data of Finnish municipalities using soRvi library
data(MML)
shp <- MML[["1_milj_Shape_etrs_shape"]][["kunta1_p"]]

# Set the projection
epsg4326String <- CRS("+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs")
proj4string(shp)<-("+init=epsg:3047")
shp2<-spTransform(shp,epsg4326String)

# Create the KML data using the shape
out<-sapply(slot(shp2,"polygons"),function(x){kmlPolygon(x,name="name",col='#df0000aa',lwd=1,border='black',description="desc") })
data<-paste(
paste(kmlPolygon(kmlname="This will be layer name", kmldescription="<i>More info about layer here</i>")$header, collapse="\n"),
paste(unlist(out["style",]), collapse="\n"),
paste(unlist(out["content",]), collapse="\n"),
paste(kmlPolygon()$footer, collapse="\n"),
sep=''
)

# Show the KML data on Google Maps
google.show_kml_data_on_maps(data)

Points on dynamic Google Maps

This examples plots buildings of Kuopio on Google Maps. User can give the minimum age of buildings to plot as an input parameter.

+ Show code - Hide code


library(rgdal)
library(RColorBrewer)
library(classInt)
library(OpasnetBaseUtils)
library(RODBC)

if (age > 190)
{
 age <- 190
}

shp <- spatial_db_query(paste('SELECT * FROM kuopio_house WHERE ika >= ',age,';',sep=''))

coordinates(shp)=c("y_koord","x_koord")

plotvar<-shp@data$ika
nclr<-8
plotclr<-brewer.pal(nclr,"BuPu")
class<-classIntervals(plotvar,nclr,style="quantile")
colcode<-findColours(class,plotclr)

epsg4326String <- CRS("+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs")
proj4string(shp)<-("+init=epsg:3067")
shp2<-spTransform(shp,epsg4326String)


kmlname<-"Kuopio house data"
kmldescription<-"Random stuff about here"
icon<-"http://maps.google.com/mapfiles/kml/pal2/icon18.png"
name<-paste("Value: ",shp2$ika)
description <- paste("<b>Age:</b>",shp2$ika,"<br><b>Building ID:</b>",shp2$rakennustunnus)

MyPointKML<-function(obj = NULL, kmlname = "", kmldescription = "", name = NULL, description = "", icon = "http://maps.google.com/mapfiles/kml/pal4/icon24.png",col=NULL) 
{
    if (is.null(obj)) 
        return(list(header = c("<?xml version=\"1.0\" encoding=\"UTF-8\"?>", 
            "<kml xmlns=\"http://earth.google.com/kml/2.2\">", 
            "<Document>", paste("<name>", kmlname, "</name>", 
                sep = ""), paste("<description><![CDATA[", kmldescription, 
                "]]></description>", sep = "")), footer = c("</Document>", 
            "</kml>")))
    if (class(obj) != "SpatialPointsDataFrame") 
        stop("obj must be of class 'SpatialPointsDataFrame' [package 'sp']")
    if (is.null(name)) {
        name = c()
        for (i in 1:nrow(obj)) name <- append(name, paste("site", 
            i))
    }

    col2kmlcolor <- function(col) paste(rev(sapply(col2rgb(col, TRUE), function(x) sprintf("%02x", x))), collapse = "")
    kml <- kmlStyle <- ""
    kmlHeader <- c("<?xml version=\"1.0\" encoding=\"UTF-8\"?>","<kml xmlns=\"http://earth.google.com/kml/2.2\">", "<Document>")
    kmlFooter <- c("</Document>", "</kml>")
    for (i in 1:nrow(obj)) {
        point <- obj[i, ]
        pt_name = name[i]
        pt_description = description[i]
        pt_style <- paste("#style", ifelse(length(icon) == 1, 1, i), sep = "")
        kml <- append(kml, "<Placemark>")
        kml <- append(kml, paste("  <description><![CDATA[",pt_description, "]]></description>", sep = ""))
	#kml <- append(kml, "<Style><IconStyle>")
	#kml <- append(kml, paste("<color>", col2kmlcolor(col[i]), "</color>", sep =""))
        #kml <- append(kml, paste("  <Icon><href>", icon, "</href></Icon>", sep = ""))
	#kml <- append(kml, "<scale>0.300000</scale>")
	#kml <- append(kml, "</IconStyle></Style>")
        kml <- append(kml, "  <Point>")
        kml <- append(kml, "    <coordinates>")
        kml <- append(kml, paste(point@coords[1], point@coords[2], sep = ","))
        kml <- append(kml, "    </coordinates>")
        kml <- append(kml, "  </Point>")
        kml <- append(kml, "</Placemark>")
    }
    
    return(paste(paste(c(kmlHeader, kmlStyle, kml, kmlFooter), sep = "", collapse = "\n"), collapse="\n", sep = ""))
    
}



data <- MyPointKML(shp2,kmlname,kmldescription,name,description,icon,colcode)
google.show_kml_data_on_maps(data)

Large quantity of points on a static Google Maps

This example plots large number of point data on static Google Maps. The map produced in this example shows the age (in years) distribution of properites within Kuopio. User can select the number of age classes (4,6 or 8) and the type of classification.