R: "Subscript out of bounds" error on function - r

Question

I continue to get an error on my function, possibly I'm overlooking something simple. I cannot run the code without getting an error when applying the function.
k.nn <- function(k,p1,p) {
k > 0
K <-length(k)
p=matrix()
for (i in p) {
matrix <- cbind(p,p1[1],p1[2])
d <- sqrt((matrix[,1]-matrix[,3])^2+(matrix[,2]-matrix[,4])^2)
}
##use the sort function to find the smallest distance from 1:k and return all nearest k values
sort.d <- function(x) { #implement bubble sort
N=length(x)
N>0
c=class(x)
for (n in length(x):2) { #distinguish the last term in the vector, name it, much be of x length, consists an error of length 1. Error if you compute n in length(x):1, cover length of 1
if(length(x)<2)
return(x)
for (m in 1:(n - 1)) { #distinguish the first term in the vector, name it
if(x[m]>x[m + 1]) { #begin comparing each term to neighboring term
swap<-x[m]
x[m]<-x[m + 1]
x[m + 1]<-swap
}
}
}
return(x)
}
sorted=sort.d(d)
for (n in k){
print(sorted[1:k])}
}
p=matrix(c(6.9,7.6,7.1,.4,6.2,1.8,2.5,2.3,5.7,6.9,.9,4.4,5.2,1.9,.6,7.4,1.2,6.6,3.3,4.9),nrow=10,ncol=2) #given matrix
p1=c(6,6)
k=3 nn.3=k.nn(k,p1,p)
print(nn.3)

Answer 1

There's a missing carriage return or ";" in the penultimate line that is throwing an error. If you remove tha last line so that you can use traceback() it tells you that k.nn throws a " subscript out of bounds" error when a matrix index is 4.
Debugging 101 tells you to put in print functions to see where the function fails and putting in a print after
c=class(x) ; print(c)
... ives you a result, but putting another one in the sort.d function does not get executed. Looking at the code upstream from that point we see:
d <- sqrt((matrix[,1]-matrix[,3])^2+(matrix[,2]-matrix[,4])^2)
So looking at the function and the matrix you have given, ... my guess is that you passed a two-column matrix to a function that expected a four-column argument.