[R] Error : Error in if (antipodal(p1, p2))

[David Winsemius]

There is a reason for the Posting Guide requesting that a reproducible  
example be offered. There is also a reason for the PG requesting that  
you not crosspost to r-help.

http://stackoverflow.com/questions/13549080/antipodal-error-in-great-circles-code

-- 
David.
On Nov 24, 2012, at 11:04 PM, shabsae wrote:

> Hey,
>
> I'm trying to build something like this
> http://flowingdata.com/2011/05/11/how-to-map-connections-with-great-circles/
> but with my own data in csv files.
> The code runs well if I use the same csv files as the author, but  
> with mine
> , this is what I get
>
> *Code*
>
> library(maps)
> library(geosphere)
>
>
> map("world")
>
> xlim <- c(-180.00, 180.00)
>
> ylim <- c(-90.00, 90.00)
>
> map("world", col = "#f2f2f2", fill = TRUE, bg = "white", lwd =  
> 0.05,xlim =
> xlim, ylim = ylim)
>
> airports <- read.csv("/Users/shabnam/Desktop/airports.csv",  
> as.is=TRUE,
> header=TRUE)
> flights <- read.csv("/Users/shabnam/Desktop/flights.csv", as.is=TRUE,
> header=TRUE)
>
> pal <- colorRampPalette(c("#545454", "white"))colors <- pal(100)
> map("world", col="#303030", fill=TRUE, bg="black", lwd=0.05,  
> xlim=xlim,
> ylim=ylim)
>
>
> fsub <- flights[flights$airline == "AA",]
>
>
> fsub <- fsub[order(fsub$cnt),]
>
> maxcnt <- max(fsub$cnt)
>
> for (j in 1:length(fsub$airline))
> {
> air1 <- airports[airports$iata == fsub[j,]$airport1,]
>
> air2 <- airports[airports$iata == fsub[j,]$airport2,]
>
> inter <- gcIntermediate(c(air1[1,]$long, air1[1,]$lat),  
> c(air2[1,]$long,
> air2[1,]$lat), n=100, addStartEnd=TRUE)
>
> colindex <- round( (fsub[j,]$cnt / maxcnt) * length(colors) )
>
> lines(inter, col=colors[colindex], lwd=0.8)
> }
>
>


David Winsemius, MD
Alameda, CA, USA