library(dtw); ### Synthetic example: check indexes, distance ldist<-matrix(1,nrow=6,ncol=6); # Matrix of ones ldist[2,]<-0; ldist[,5]<-0; # Mark a clear path of zeroes ldist[2,5]<-.01; # Forcely cut the corner ds<-dtw(ldist); # DTW with user-supplied local cost matrix ds$distance # 2 ds$index1 # 1 2 2 2 2 3 4 5 6 6 ds$index2 # 1 1 2 3 4 5 5 5 5 6 da<-dtw(ldist,step=asymmetric); # Also compute the asymmetric da$distance # 2 da$index1 # 1 2 3 4 5 6 da$index2 # 1 3 5 5 5 6 da<-dtw(ldist,step=asymmetricP0); # The strange aP0 alignment da$distance # 1 da$index1 # 1 2 2 2 2 3 4 5 6 6 da$index2 # 1 1 2 3 4 5 5 5 5 6 ds<- dtw:::globalCostMatrix(ldist) dsn<- dtw:::globalCostMatrix(ldist,native=FALSE) stopifnot(all.equal(ds,dsn)) # TRUE ### Sine/cosine example: verify native output ### there may be a random chance of failing due to rounding errors idx<-seq(0,6.28,len=100); query<-sin(idx)+runif(100)/10; template<-cos(idx) ldist<-outer(query,template,FUN=function(x,y){(x-y)^2}) ds<- dtw:::globalCostMatrix(ldist) dsn<- dtw:::globalCostMatrix(ldist,native=FALSE) all.equal(ds,dsn) # TRUE ### Use proxy::dist query <- cbind(1:10,1) ref <- cbind(11:15,2) cxdist <- proxy::dist(query,ref,method="Manhattan") d1 <- dtw(query,ref,dist.method="Manhattan")$distance d2 <- dtw(cxdist)$distance stopifnot(d1==d2) ### See if DTW is registered in proxy::dist lambda <- dist(query,ref,method="DTW") stopifnot(sum(lambda)==470)