Hello, I would like to know more about how to use the "apply" family and have attempted to convert nested "for" loops in example code from Contributed Documentation ("The Friendly Beginners' R Courseā by Toby Marthews (ZIP, 2007-03-01)") to an "apply" function(s). The relevant code is:
distances=c(51,65,175,196,197,125,10,56) #distances of 8 houses from the town centre in m bearings=c(10,8,210,25,74,128,235,335) #bearings of the houses in degrees xpos=distances*sin(bearings*pi/180) #in sin and cos the argument MUST be in radians ypos=distances*cos(bearings*pi/180) numpoints=length(distances) nnd=rep(sqrt(2*400*400),times=numpoints) #start with the maximum possible distance for (i in 1:numpoints) { for (j in 1:numpoints) { if (i!=j) { diffx=abs(xpos[i]-xpos[j]) diffy=abs(ypos[i]-ypos[j]) nd=sqrt((diffx^2)+(diffy^2)) if (nd ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.