R/get_dist_matrix.R

In Gabegit/gmdata: My some useful functions for data tools.

#' get cities' distance maxtrix
#' @param cities vector
#' @return a distance matrix
#' @export
#' @examples
#' mydat = get_dist_matrix(c("长沙","南昌","郑州","武汉","太原","广州","福州","上海"))
#'

get_dist_matrix <- function(cityname){
	library(gmdata)

	# get a long and lat data.frame
	myda <- gmdata::get_long_lat_Baidu(cityname)

	# calculate the distance matrix
	nrows <- dim(myda)[1]
	print(nrows)
	ncols <- dim(myda)[2]
	print(ncols)

	#library(dplyr)
	for (i in 1:(nrows-1)){
		colnew <- myda$cities[i]
		print(colnew)

		myda[colnew] = NA

		for (j in (i+1):nrows){
			myda[j,i+3] <- gmdata::get_city_dist(myda[i,2],myda[i,3],myda[j,2],myda[j,3])$haversine
		}

	}
	return(myda)

}