Random Geographic Coordinates Sampling

Generate the specified number of random geographic coordinates from a rectangular space defined by minimum and maximum X (Longitude) and Y (Latitude) coordinates. Input and output coordinates are in decimal degrees, with a specified precision of output values.

No results

				######################################
# Program to do random geographic coordinates sampling
######################################
rm(list = ls())

# cat("
Test:",length(commandArgs()))
test<- ifelse(length(commandArgs()) == 2, TRUE, FALSE)
fpath<- ifelse(test, "webRootUrl", "rtoolsPath")

# load header scripts
  source(paste(fpath, "R/epi_head.R", sep = ""))
  source(paste(fpath, "R/HTMLStream.R", sep = ""))
  source(paste(fpath, "R/epitools_functions.r", sep = ""))

# extract command arguments 
# 1 = number of points, 2 = minX, 3 = maxX, 4 = minY, 5 = maxY, 6 = precision 
# cat("
", a0[8:13])
    a1<- type.convert(a0[8:13])
# cat("
", a1)

n<- a1[1]           # sample size
minX<- min(a1[2], a1[3])           # minimum X
maxX<- max(a1[2], a1[3])          # maximum X
minY<- min(a1[4], a1[5])          # minimum Y
maxY<- max(a1[4], a1[5])           # maximum Y
digits<- a1[6]        # precision
heading<- "RGCS Random sampling results"
heading2<- "List of randomly selected points"

filename<- digest(Sys.time())
tmp.path<- paste(fpath, "tmp/", sep = "")
tmp.file<- paste(fpath, "tmp/", filename, sep = "")
sinkfile<- paste(fpath, "tmp/", filename, ".txt", sep="")   # fpath,
# cat("
", data.file)

inputs<- array(a1, dim = c(length(a1), 1))
rownames(inputs)<- c("Sample size", "Minimum X", "Maximum X", 
                  "Minimum Y", "Maximum Y", "Precision")

# do random sampling
x<- runif(n, minX, maxX)
y<- runif(n, minY, maxY)
ran.list<- round(cbind(x, y), digits)
ran.list<- ran.list[order(ran.list[,1]),]


# ran.list

file.name<- file(paste(tmp.file, "_result.xls", sep = ""), open = "wt")
  writeLines(c(heading, date(), ""), con = file.name)
  writeLines("Inputs", con = file.name)
  write.table(inputs, file = file.name, sep = "\t", append = T, col.names = F)    
  writeLines(c("", heading2), con = file.name)
  write.table(ran.list, file = file.name, sep = "\t", append = T, row.names = F)    
close(file.name)


# output results
d1<- paste(substr(date(), 1, 10), substr(date(), 20,24), " @", substr(date(), 11, 16))
# reformat headers
output<- paste("
", heading, "
\n")
output<- paste(output, "
", "Analysed: ", d1, "
\n", sep="")
output<- paste(output, "
Inputs
\n")
output<- paste(output, HTMLStream(inputs, cellborder = 0, classfirstline = "mbg", classfirstcolumn = "mbg", classcellinside = "left_mar",  cellalign = "center", align = "left"))
output<- paste(output, "
Results
\n")
output<- paste(output, "
", heading2, "
\n")
output<- paste(output, HTMLStream(ran.list, cellborder = 0, classfirstline = "mbg", classfirstcolumn = "mbg", classcellinside = "left_mar",  cellalign = "center", align = "left"))
output<- paste(output, "
Download excel file of results
\n")
output<- paste(output, "Detailed results
\n", sep = "")
# nrow(ran.list)



# sink()
# write output to file
file.name<- file(paste(tmp.file, "_result.html", sep = ""), open = "wt")
cat(output, file=file.name)  
close(file.name)           #)
cat(output)