A function to project data on a bestfitting transect line

project_on_transect(x, y)

Arguments

x	x coordinate of points
y	y coordinate of points

Value

xp x coordinate of points projected on the transect

yp y coordinate of points projected on the transect

xt x coordinate along the transect (new coordinate x)

yt y coordinate corresponding to the distance to the transect (new coordinate y)

slopexy slope of transect

interceptxy intercept of transect

Examples

x=c(-73.1,-57.4,-54.6,-32.4,-13.9,  9.9, 46.8, 59.3, 91.8, 47.3)
y=c(-73.8,-57.6,-23.5,-20.6,-22.1,-41.9,-49.7,-26.3,-5.75,-34.1)
res=project_on_transect(x,y)
plot(x,y,col="blue",
     xlim=range(c(x,res$xt)),
     ylim=range(c(y,res$yt)))
abline(b=res$slopexy,a=res$interceptxy, col="red")
points(res$xp,res$yp, col="red")