[R] Help for looping

[tkobayas at indiana.edu]

Rusers:

I have tried to minimize computing times by taking advanage of 
lapply(). My data is a 1000*30 matrix and the distance matrix was 
created with dist(). What I am trying to do is to compute the standard 
distances using the frequencies attached to the nearest negibors of n 
reference zones. So I will have 1000 standard distances, and would like 
to see the frequency distribution of the standard distances.

# Convert decimal degrees into UTM miles
x<-(data[,1]-58277.194363)*0.000621
y<-(data[,2]-4414486.03135)*0.000621

# Combine x y for computing distances
coords<-cbind(x,y)
pts<-length(data)

# Subset housing data and employment data
RES<-data[,3:17]
EMP<-data[,378:392]

# Combine all the subdata as D
D<-cbind(coords,RES,EMP)

cases<-ncol(D)-ncol(coords)

# Create a threshold bandwidth for defining the nearest neighbors
thrs<-seq(0,35,by=1)

SDTAZ<-rep(list(matrix(,nrow(D),length(thrs))),cases)


for (j in 1:nrow(D))
for (k in 1:length(thrs))
for (l in 1:cases)
{
{
{

SDTAZ[[l]][j,k]<-
sqrt(
   sum(
	(D[as.vector(which(dis[j,]<=thrs[k])),l+2]-D[j,l+2]-
          min(D[as.vector(which(dis[j,]<=thrs[k])),l+2]-D[j,l+2])+1)*
         (
	   (dis[j,as.vector(which(dis[j,]<=thrs[k]))])^2
         )
      )

	/sum(D[as.vector(which(dis[j,]<=thrs[k])),l+2]-D[j,l+2]-
         min(D[as.vector(which(dis[j,]<=thrs[k])),l+2]-D[j,l+2])+1)
		)
}
}
}

I think that within this nested loop, I should use lapply() but I ended 
up getting different values.... I appreciate if someone could kindly 
help me.

Thank you very much.
------------------------------------
Takatsugu Kobayashi
PhD Candidate
Indiana University, Dept. Geography