Example of adding to an ordination
A fitted ordination for use in the example for addord
. Many of the functions in ecodist
take a long time to run, so prepared examples have been included.
data(iris.fit)
The format of this object is a list with: X1, X2, etc: ordination configuration: coordinates for each point. stress: goodness of fit for each point. isTrain: logical vector indicating whether each point was used in the original ordination.
Sarah Goslee
data(iris) iris.d <- dist(iris[,1:4]) ### nmds() is timeconsuming, so this was generated ### in advance and saved. ### set.seed(1234) ### iris.nmds <- nmds(iris.d, nits=20, mindim=1, maxdim=4) ### save(iris.nmds, file="ecodist/data/iris.nmds.rda") data(iris.nmds) # choose the best two-dimensional solution to work with iris.nmin <- min(iris.nmds, dims=2) # generate new data points to add to the ordination # this might be new samples, or a second dataset iris.new <- structure(list(Sepal.Length = c(4.6, 4.9, 5.4, 5.2, 6, 6.5, 6, 6.8, 7.3), Sepal.Width = c(3.2, 3.5, 3.6, 2.3, 2.8, 3, 2.7, 3.1, 3.2), Petal.Length = c(1.2, 1.5, 1.5, 3.5, 4.1, 4.2, 4.8, 5, 5.7), Petal.Width = c(0.26, 0.26, 0.26, 1.2, 1.3, 1.4, 1.8, 2, 2), Species = structure(c(1L, 1L, 1L, 2L, 2L, 2L, 3L, 3L, 3L), .Label = c("setosa", "versicolor", "virginica"), class = "factor")), .Names = c("Sepal.Length", "Sepal.Width", "Petal.Length", "Petal.Width", "Species"), class = "data.frame", row.names = c(NA, -9L)) # provide a dist object containing original and new data # provide a logical vector indicating which samples were used to # construct the original configuration iris.full <- rbind(iris, iris.new) all.d <- dist(iris.full[,1:4]) is.orig <- c(rep(TRUE, nrow(iris)), rep(FALSE, nrow(iris.new))) ### addord() is timeconsuming, so this was generated ### in advance and saved. ### set.seed(1234) ### iris.fit <- addord(iris.nmin, iris.full[,1:4], all.d, is.orig, maxit=100) ### save(iris.fit, file="ecodist/data/iris.fit.rda") data(iris.fit) plot(iris.fit$conf, col=iris.full$Species, pch=c(18, 4)[is.orig + 1], xlab="NMDS 1", ylab="NMDS 2") title("Demo: adding points to an ordination") legend("bottomleft", c("Training set", "Added point"), pch=c(4, 18)) legend("topright", levels(iris$Species), fill=1:3)
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