[R] Help with Nested loop - very slow, can I use an apply?

[dolar]

Hi there

I have two tables, with longitudinal and latitudinal coordinates. what I
want is a cross table between each coordinate, to find the distance between
each building and different landmarks


I currently have this nested loop which is fine for when i have 10 stores of
interest, against 200 other landmarks and uses pythagarus to find the
distance


for(i in 1:nrow(store_c)){
	landmark_store_cross_tab$foo=landmark_c$landmark_name
	for (j in 1:nrow(landmark_c)){
	landmark_store_cross_tab[j,i+1]=sqrt((landmark_c$x[j]-store_c$x[i])^2
		+(landmark_c$y[j]-store_c$y[i])^2)/1000
}
names(landmark_store_cross_tab)[i+1]=store_c$store_name[i]
}

can someone suggest how I can make this faster?


I am hoping to use one of the apply functions

Thanks

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