a

twoWay <- function(Y,k){
NPOPS<-dim(X)[1]

ID <- vector(length=NPOPS)
ID[1:NPOPS] <- c(as.matrix(row.names(X)))


 X <- X[,1:25]

if (length(Y)==1)
Y <- X[which(ID==Y),]


YDIST<-vector(length=NPOPS+NPOPS*(NPOPS-1)/2)




XDIST <- as.matrix(dist(X))

for (i in 1:NPOPS)
YDIST[i] <- sqrt(sum((Y-X[i,])^2))

ID2 <- vector()
YDIST2 <- vector()
COUNT <- NPOPS

        for (i in 1:(NPOPS-1))
        for (j in (i+1):NPOPS) {
            COUNT<-COUNT+1
            if (abs(YDIST[i]-YDIST[j])<XDIST[i,j] & YDIST[i]>0 & YDIST[j]>0) {
                FRAC <- (XDIST[i,j]^2+YDIST[i]^2-YDIST[j]^2)/(2*XDIST[i,j]^2)
                if (FRAC>=0 & FRAC<=1) {
                    YDIST2[COUNT] <- sqrt(YDIST[i]^2-FRAC^2*XDIST[i,j]^2)
                    ID2[COUNT] <- paste(round(100*(1-FRAC),1),"% ",ID[i]," + ",round(100*FRAC,1),"% ",ID[j],sep=" ")
                    }
                else
                YDIST2[COUNT]<- 100
                }
            else
            YDIST2[COUNT]<- 100
            }


ORDER<-order(YDIST2)
ORDER<-cbind(ID2[ORDER[1:k]],round(YDIST2[ORDER[1:k]],4))
print(ORDER)
}