snpgdsCutTree {SNPRelate} | R Documentation

## Determine clusters of individuals

### Description

To determine sub groups of individuals using a specified dendrogram from hierarchical cluster analysis

### Usage

    snpgdsCutTree(hc, z.threshold=15, outlier.n=5, n.perm = 5000, samp.group=NULL,
        col.outlier="red", col.list=NULL, pch.outlier=4, pch.list=NULL,
        label.H=FALSE, label.Z=TRUE, verbose=TRUE)

### Arguments

`hc` | an object of `snpgdsHCluster`
`z.threshold` | the threshold of Z score to determine whether split the node or not
`outlier.n` | the cluster with size less than or equal to `outlier.n` is considered as outliers
`n.perm` | the times for permutation
`samp.group` | if `NULL`, determine groups by Z score; if a vector of factor, assign each individual in dendrogram with respect to `samp.group`
`col.outlier` | the color of outlier
`col.list` | the list of colors for different clusters
`pch.outlier` | plotting 'character' for outliers
`pch.list` | plotting 'character' for different clusters
`label.H` | if TRUE, plotting heights in a dendrogram
`label.Z` | if TRUE, plotting Z scores in a dendrogram
`verbose` | if TRUE, show information

### Details

The details will be described in future.

### Value

Return a list:

`sample.id` | the sample ids used in the analysis
`z.threshold` | the threshold of Z score to determine whether split the node or not
`outlier.n` | the cluster with size less than or equal to `outlier.n` is considered as outliers
`samp.order` | the order of samples in the dendrogram
`samp.group` | a vector of factor, indicating the group of each individual
`dmat` | a matrix of pairwise group dissimilarity
`dendrogram` | the dendrogram of individuals
`merge` | a data.frame of `(z, n1, n2)` describing each combination: `z`, the Z score; `n1`, the size of the first cluster; `n2`, the size of the second cluster
`clust.count` | the counts for clusters

### Author(s)

Xiuwen Zheng

### See Also

`snpgdsHCluster`, `snpgdsDrawTree`, `snpgdsIBS`, `snpgdsDiss`

### Examples

    # open an example dataset (HapMap)
    genofile <- snpgdsOpen(snpgdsExampleFileName())

    pop.group <- as.factor(read.gdsn(index.gdsn(
        genofile, "sample.annot/pop.group")))
    pop.level <- levels(pop.group)

    diss <- snpgdsDiss(genofile)
    hc <- snpgdsHCluster(diss)

    # close the genotype file
    snpgdsClose(genofile)

    ###################################################################
    # cluster individuals
    #

    set.seed(100)
    rv <- snpgdsCutTree(hc, label.H=TRUE, label.Z=TRUE)

    # the distribution of Z scores
    snpgdsDrawTree(rv, type="z-score", main="HapMap Phase II")

    # draw dendrogram
    snpgdsDrawTree(rv, main="HapMap Phase II",
        edgePar=list(col=rgb(0.5,0.5,0.5, 0.75), t.col="black"))

    ###################################################################
    # or cluster individuals by ethnic information
    #

    rv2 <- snpgdsCutTree(hc, samp.group=pop.group)

    # cluster individuals by Z score, specifying 'clust.count'
    snpgdsDrawTree(rv2, rv$clust.count, main="HapMap Phase II",
        edgePar = list(col=rgb(0.5,0.5,0.5, 0.75), t.col="black"),
        labels = c("YRI", "CHB/JPT", "CEU"), y.label=0.1)
    legend("bottomleft", legend=levels(pop.group), col=1:nlevels(pop.group),
        pch=19, ncol=4, bg="white")

    ###################################################################
    # zoom in ...
    #

    snpgdsDrawTree(rv2, rv$clust.count, dend.idx = c(1),
        main="HapMap Phase II -- YRI",
        edgePar=list(col=rgb(0.5,0.5,0.5, 0.75), t.col="black"),
        y.label.kinship=TRUE)

    snpgdsDrawTree(rv2, rv$clust.count, dend.idx = c(2,2),
        main="HapMap Phase II -- CEU",
        edgePar=list(col=rgb(0.5,0.5,0.5, 0.75), t.col="black"),
        y.label.kinship=TRUE)

    snpgdsDrawTree(rv2, rv$clust.count, dend.idx = c(2,1),
        main="HapMap Phase II -- CHB/JPT",
        edgePar=list(col=rgb(0.5,0.5,0.5, 0.75), t.col="black"),
        y.label.kinship=TRUE)

[Package SNPRelate version 1.24.0 Index]