https://github.com/cran/dtw
Tip revision: 935e521fa862c893e52a85dbb72c3ae53246a8e4 authored by Toni Giorgino on 15 August 2009, 00:00:00 UTC
version 1.14-3
version 1.14-3
Tip revision: 935e521
dtw_test.R
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)