Hotspot Detection with trees"
In TreeHotspots: Hotspot Detection using Classification Trees

knitr::opts_chunk$set(echo = TRUE)

#source('H:/DropboxHWR/Coding/Rpackages/treehotspotspackage/TreeHotspots/R/list.rules.R')
#source('H:/DropboxHWR/Coding/Rpackages/treehotspotspackage/ExtraCode/Mobsters.R')

Unimodal "bump"

library(TreeHotspots)
library(partykit)
suppressMessages(library(PBSmapping, quietly = TRUE))

N = 500;
set.seed(50);
#spherical 
Bump1 <- cbind(x=rnorm(N,0,.45), y=rnorm(N,0,.45),l=1);#center at (0,0)

Bckgr <- cbind(x=runif(2*N,-4,4), y=runif(2*N,-4,4),l=0);#center at (0,0);
data1 <- as.data.frame(rbind(Bump1, Bckgr));
data1$l = factor(data1$l)

# mb <- glmtree(l ~ x + y, data = data1, family = binomial, minsize = 100, prune = "BIC")
# plot(mb)
#  plot(y ~ x, col = as.numeric(l), data = data1, cex = 0.5, pch=20,main="glmtree")
# PartitionParty(mb,vars=c("x","y"), verbose=0)

  library(rpart)
 rp = rpart(l ~ x + y, data = data1)
 #plot(rp)
 party_rp <- as.party(rp)
 plot(party_rp)

 plot(y ~ x, col = as.numeric(l), data = data1, cex = 0.5, pch=20,main="rpart")
 PartitionParty(party_rp,vars=c("x","y"), verbose=0)

 # mb <- glmtree(l ~ x + y, data = data1, family = binomial, minsize = 100, prune = "BIC")
 # plot(mb)
 # 
 # plot(y ~ x, col = as.numeric(l), data = data1, cex = 0.5, pch=20)
 # PartitionParty(mb,vars=c("x","y"), verbose=0)

very elliptical:

library(MASS)
(Sigma <- matrix(c(1,0.85,0.85,1),2,2))
Bump2 = cbind(mvrnorm(n = N, rep(0, 2), Sigma),l=1)
colnames(Bump2)[1:2] = c("x","y")
#Bump2 <- cbind(x=rnorm(N/2,0,.75), y=rnorm(N/2,0,.75),l=0);#center at (0,0)
data2 <- as.data.frame(rbind(Bump2, Bckgr));
data2$l = factor(data2$l)
COLS = rgb(0:1,rep(0,2),1:0, 0.5);

 rp = rpart(l ~ x + y, data = data2)
 #plot(rp)
 party_rp <- as.party(rp)
 plot(party_rp)

 plot(y ~ x, col = as.numeric(l), data = data2, cex = 0.5, pch=20,main="rpart")
 PartitionParty(party_rp,vars=c("x","y"), verbose=0)

Artifial data at multiple scales and angles:

# 
 set.seed(123)
  library(mvtnorm)
  cov1 = sigma = matrix(2*c(1,-0.9,-0.9,1),ncol=2)
  Clus1 = rmvnorm(100,mean=c(X=10,Y=10), sigma = cov1)
  #TestRotation(Clus1, center=colMeans(Clus1))
  cov2 = sigma = matrix(0.5*c(1,0.9,0.9,1),ncol=2)
  Clus2 = rmvnorm(100,mean=c(X=3,Y=3), sigma = cov2)
  cov3 = sigma = matrix(c(0.1,0,0,0.1),ncol=2)
  Clus3 = rmvnorm(100,mean=c(X=6,Y=8), sigma = cov3)
  msdata = rbind.data.frame(Clus1,Clus2,Clus3)
  #TestRotation(msdata, center=colMeans(msdata[,1:2]))
  colnames(msdata) = c("lon","lat")
  rx = range(msdata[,"lon"])
  ry = range(msdata[,"lat"])
  msdata[,"clus"] = rep(1:3,each=100)
  N=300
  Bckgr = cbind.data.frame(lon= runif(N,rx[1],rx[2]),
                           lat= runif(N,ry[1],ry[2]),
                           clus=0)
  #alternatively, regular grid:
  # N1=N2=N0 = round(sqrt(N))
  # Bckgr =expand.grid(lon= seq(rx[1],rx[2],length=N1),
  #                     lat= seq(ry[1],ry[2],length=N2),
  #                     clus=0)

  msdata=rbind.data.frame(msdata,Bckgr)
  msdata$clus = factor(msdata$clus)
  #plot(lat~lon, data=msdata, col = clus+1, pch = 20,cex=0.75)

  ct <- ctree(clus ~ lon+lat,data = msdata)

  plot(ct)
  plot(lat ~ lon,data = msdata, col = clus, pch=20,cex=0.6,main="ctree")
  PartitionParty(ct,vars=c("lon","lat"), verbose=0)

  rp = rpart(clus ~ lon+lat,data = msdata, control=rpart.control(minbucket=40,cp=0.01))
 #plot(rp)
 party_rp <- as.party(rp)
 plot(lat ~ lon,data = msdata, col = clus, pch=20,cex=0.6,main="rpart")
PartitionParty(party_rp,vars=c("lon","lat"), verbose=0)


 clusts = FindClusters(clus ~ lon+lat,msdata,minsize=50,minArea=NULL,
                       maxArea=NULL,ORfilter=list(OR=FALSE,OR1=NULL,OR2=NULL),
                         PLOT=0, verbose = 0)
 #points(lon~lat,data=msdata,col=as.numeric(msdata[,"clus"]),pch=20,cex=.7)

Old Faithful Geyser data set

  library(tree)
  data(faithful, env = environment())

  n = nrow(faithful)
  faithful[,"Cluster"] = 1#faithfulMclust$classification
  N=400
  Bckgr = cbind.data.frame(eruptions= runif(N,min(faithful[,"eruptions"]),max(faithful[,"eruptions"])),
                           waiting= runif(N,min(faithful[,"waiting"]),max(faithful[,"waiting"])),
                           Cluster=0)
  faithful=rbind.data.frame(faithful,Bckgr)

  ftr=tree(as.factor(Cluster) ~ eruptions+waiting,faithful, 
           mincut=40)
  partition.tree(ftr, ordvars=c("eruptions","waiting"))
  points(waiting~eruptions, data = faithful,pch=20, cex=0.5, col = Cluster+1)
  tp = TreePartition(ftr, ordvars=c("eruptions","waiting"))
  PlotPartition(tp,lab=TRUE)
  ii = which(tp[,"maxClass"] %in% 1 | rownames(tp) == "rect0")
  PlotPartition(tp[ii,],lab=TRUE, col = c(0, 2:(length(ii))))

map overlay:

data("drugCrimes")
library("RgoogleMaps")
  drugCrimes$MATCH = factor(drugCrimes$MATCH)

  rp = rpart(MATCH ~ X+Y,data = drugCrimes, control=rpart.control(minbucket=40,cp=0.01))
 party_rp <- as.party(rp)
 plot(party_rp)
 ranRows=sample(nrow(drugCrimes),10000)
 plot(Y~X,data=drugCrimes[ranRows,],col=AddAlpha(4-as.numeric(MATCH)),pch=20,cex=0.6)
 PartitionParty(party_rp,vars=c("X","Y"), verbose=0)


spot1 = getHotspots(MATCH ~ X+Y,drugCrimes)
 CrimesInClus = DataInsideBox(spot1[1:5,],drugCrimes)
 mean(as.numeric(CrimesInClus$MATCH))-1

 #plot(Y~X,data=drugCrimes[ranRows,],col=AddAlpha(4-as.numeric(MATCH)),pch=20,cex=0.6)
 #addPolys(spot1[1:5,],density=NULL)

 plotPolys(spot1[1:5,],density=NULL,xlim=range(drugCrimes$X),ylim=range(drugCrimes$Y),border="blue",lwd=2)
 points(Y~X,data=drugCrimes[ranRows,],col=AddAlpha(4-as.numeric(MATCH)),pch=20,cex=0.6)

 ct=ctree(MATCH ~ X+Y,data = drugCrimes)
 #plot(ct)
 Leafs = PartitionParty(ct, c("X","Y"), PLOT=F)

 # LeafProbs = tapply(as.numeric(drugCrimes$MATCH), predict(ct,type="node"), function(y) prop.table(y))
 # 
 LeafProbs = sort(tapply(as.numeric(drugCrimes$MATCH), predict(ct,type="node"), function(y) mean(y)),decreasing=TRUE)

 NN = table(predict(ct,type="node"))

 #Leafs[["146"]]
 for (i in 1:10){
   n = names(LeafProbs)[i]
   m= matrix(Leafs[[n]][-1,],nrow=1)
   colnames(m) = c("xleft","ybottom", "xright", "ytop")
   m2 = Rect2PBSpolys(m)
   a= calcArea(m2)$area
   if (a > 10^(-6) & NN[n]> 100)  {
     cat("node ID", n, format(a,digits = 2),NN[n],"\n")
     addPolys(m2,density=1, border = i)
   }
 }

 #AllSpots = FindClusters(MATCH ~ X+Y,drugCrimes, minArea=10^(-6))
 #AllSpots = getHotspots(MATCH ~ X+Y,drugCrimes, minArea=10^(-7),ORfilter=list(OR=TRUE,OR1=NULL,OR2=NULL),verbose=2)
 #clearly sth. is terribly wrong here:
 #addPolys(AllSpots,border="blue",density=NULL)

 #on map:
 SFmap = GetMap.bbox(lonR=c(-122.4266, -122.41),latR=c(37.72, 37.8))
 PlotOnStaticMap(SFmap,lon=drugCrimes$X[ranRows],lat=drugCrimes$Y[ranRows],
                 col=AddAlpha(4-as.numeric(drugCrimes$MATCH)[ranRows]),pch=20,cex=0.6)

Interactive Maps

   m1= matrix(Leafs[["79"]][-1,],nrow=1)
  colnames(m1) = c("xleft","ybottom", "xright", "ytop")
  m2 = Rect2PBSpolys(m1)


library("leaflet")

m = leaflet() %>% addTiles()

# move the center to SF 
m = m %>% setView(-122.42, 37.77, zoom = 13)

# circle (units in metres)
x = subset(drugCrimes[ranRows,],MATCH == 0)
y = subset(drugCrimes[ranRows,],MATCH == 1)
m %>% addCircleMarkers(x$X,x$Y , color=3, radius = 1) %>% addCircleMarkers(y$X,y$Y , color=2, radius = 1) %>% addPolygons(m2$X, m2$Y, layerId = 'hotspot1')