run_pca_cc_genes {tricycle} | R Documentation

## Run PCA on Gene Ontology cell cycle genes

### Description

Run PCA on Gene Ontology cell cycle genes abd get a new SingleCellExperiment. User could use this function to learn new reference projection matrix.

### Arguments

`sce.o` | A SingleCellExperiment contains library size normalized **log-expression** matrix.
`gname` | Alternative rownames of `sce.o`. If provided, this will be used to map genes within Gene Ontology cell cycle gene list. If not provided, the rownames of `sce.o` will be used instead. Default: NULL
`exprs_values` | Integer scalar or string indicating which assay of `sce.o` contains the **log-expression** values, which will be used to run PCA. Default: 'logcounts'
`gname.type` | The type of gene names as in `gname` or rownames of `sce.o`. It can be either 'ENSEMBL' or 'SYMBOL'. Default: 'ENSEMBL'
`species` | The type of species in `sce.o`. It can be either 'mouse' or 'human'. If the user uses custom `cycleGene.l`, this value will have no effect. Default: 'mouse'
`AnnotationDb` | An AnnotationDb objects. It is used to map ENSEMBL IDs to gene SYMBOLs. If no AnnotationDb object being given, the function will use `org.Hs.eg.db` or `org.Mm.eg.db` for human and mouse respectively.
`ntop` | The number of genes with highest variance to use when calculating PCA, as in `calculatePCA`. Default: 500
`ncomponents` | The number of component components to obtain, as in `calculatePCA`. Default: 20
`name` | String specifying the name to be used to store the result in the `reducedDims` of the output. Default: 'PCA'

### Details

The function require an output of a SingleCellExperiment object which contains the library size normalized **log-expression** matrix. The full dataset will be subsetted to genes in the Gene Ontology cell cycle gene list (GO:0007049). The corresponding AnnotationDb object will be `org.Mm.eg.db` and `org.Hs.eg.db` for mouse and human respectively. If `runSeuratBy` is set, the data will be integrated to remove batch effect between samples/batches by Seurat.

User can use this function to make new reference projection matrix by getting the 'rotation' attribute in PCA results. Such as `attr(reducedDim(sce.o, 'PCA'), 'rotation')[, 1:2]`. See examples for more details.

### Value

A subset SingleCellExperiment object with only GO cell cycle genes will be return. The PCA resulting will be save in reducedDims with chosen name `reducedDims(..., name)`. If Seurat integration is performed, another reducedDims with name 'matched.'+`name` will also be included in the SingleCellExperiment.

### Author(s)

Shijie C. Zheng

### Examples

    data(neurosphere_example, package = "tricycle")
    ### Use internal NeuroRef to project and infer tricyclePosition
    neurosphere_example <- estimate_cycle_position(neurosphere_example)

    ### Build new reference
    gocc_sce.o <- run_pca_cc_genes(neurosphere_example)
    new.ref <- attr(reducedDim(gocc_sce.o, "PCA"), "rotation")[, seq_len(2)]

    ### Use new reference to project and infer tricyclePosition
    new_sce <- estimate_cycle_position(neurosphere_example, ref.m = new.ref,
     dimred = "tricycleEmbedding2")
    plot(neurosphere_example$tricyclePosition, new_sce$tricyclePosition)

[Package tricycle version 1.2.1 Index]