R Notebook

# Make interpolation

Warning messages:
1: In readChar(file, size, TRUE) : truncating string with embedded nuls
2: In readChar(file, size, TRUE) : truncating string with embedded nuls
3: In readChar(file, size, TRUE) : truncating string with embedded nuls
4: In readChar(file, size, TRUE) : truncating string with embedded nuls
5: In readChar(file, size, TRUE) : truncating string with embedded nuls

library(raster)
library(sp)

Points<-shapefile("F:\\Research\\Research_Cooperation\\ILRI_Mosquito_Mapping\\Mosquito\\Mosquito_Sampling\\Mosquito_Final.shp") # Upload mosquito points

VN<-getData(name="GADM",country="Vietnam",level=1) # Levels 1 VN, Level 2 province, Level 3 means communes

HN1<-VN[VN$VARNAME_1=='Ha Noi',]

Mosquito<-spTransform(Points,CRSobj = "+proj=utm +zone=48N +datum=WGS84 +units=m +no_defs +ellps=WGS84 +towgs84=0,0,0

")

HN<-spTransform(HN1,CRSobj = "+proj=utm +zone=48N +datum=WGS84 +units=m +no_defs +ellps=WGS84 +towgs84=0,0,0

")

# Create empty raster 

df<-as.data.frame(spsample(HN,n=1000,type = "regular",cellsize=30))

names(df)<-c("X","Y")
coordinates(df)<-c("X","Y")
gridded(df)<-T
fullgrid(df)<-T
proj4string(df)<-proj4string(Mosquito)

library(gstat)

interpolate <- gstat::idw(Counts ~ 1, Mosquito, newdata=df, idp=2.0)

[inverse distance weighted interpolation]

ras<-raster(interpolate)

Mos_inte<-mask(ras,HN)

plot(Mos_inte)