distance<-function(x,y,m,q) { abs((y-m*x-q)/sqrt(m^2+1)) } 
aligned <- function(x,y,e)
{
	rl <- lm(y~x);
	m <- as.numeric(rl[[1]][2]);
	q <- as.numeric(rl[[1]][1]);
	d <- distance(x,y,m,q)<e;
	tmp <- TRUE;
	for(i in d) tmp <- tmp & i;
	tmp
} 
distances <- function(x,y)
{
	rl <- lm(y~x);
	m <- as.numeric(rl[[1]][2]);
	q <- as.numeric(rl[[1]][1]);
	distance(x,y,m,q)
}

e<-25

db<-read.csv(file="C:\\coordinates.csv",sep=";",header=T)
attach(db)

points<-c(16,85,89,94)
plot(x,y,col="white")
for(i in points)
{
	points(x[i],y[i],col="dark red",pch=19)
	text(x[i],y[i],name[i],cex=0.5,pos=1)
	text(x[i],y[i],i,cex=0.5,pos=3)
}
px<-x[points]
py<-y[points]
aligned(px,py,e)
rl <- lm(py~px)
abline(rl) 
points
distances(px,py)