R/triang_fun.R

In JannisGottwald/N40RTS: What the Package Does (One Line, Title Case)

#' triangulate
#'
#' @export
#'









triang <- function(x1,y1,alpha1,x2,y2,alpha2){
  # For Triangulation GK Coordinates are necesarry!
  # First calculate tan keeping in mind that 0° in geo-coordinates are 90° in a x-y plane
  ta1 <- (alpha1%%360)/180*pi
  ta2 <- (alpha2%%360)/180*pi
  if(((alpha1-alpha2)%%180)==0){#print("No triangulation possible: all three points are on one line")
    return(c(NA,NA))}
  
  # Findinf Intersection Using solver
  b<-c(x2-x1,y2-y1)
  a1<-c(sin(ta1),cos(ta1))
  a2<-c(-sin(ta2),-cos(ta2))
  a<-matrix(c(a1,a2),nrow=2)
  l<-solve(a,b)
  px<-x1+l[1]*sin(ta1)
  py<-y1+l[1]*cos(ta1)
  
  if(l[2]>0&l[1]>0)
  {
    return(data.frame(x=px,y=py))
  }
  else{
    return(data.frame(x=NA,y=NA))
  }
}