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Plot Principal Component Analysis (PCA) of samples

Usage

plot_PCA(
  exp,
  metadata,
  metadata_cols = NULL,
  log_trans = FALSE,
  PCs = c(1, 2),
  size = 2
)

Arguments

exp

A gene expression data frame with genes in row names and samples in column names or a `SummarizedExperiment` object.

metadata

A data frame of sample metadata containing sample names in row names and sample annotation in subsequent columns. Ignored if `exp` is a `SummarizedExperiment` object, since colData will be automatically extracted.

metadata_cols

A vector (either numeric or character) indicating which columns should be extracted from column metadata if exp is a `SummarizedExperiment` object. The vector can contain column indices (numeric) or column names (character). By default, all columns are used.

log_trans

Logical indicating whether the gene expression matrix should be log transformed using log(exp + 1). Default: FALSE.

PCs

Numeric vector of length 2 indicating the principal components to be plotted on the x-axis and y-axis, respectively. Default: c(1, 2).

size

Numeric indicating the point size. Default is 2.

Value

A ggplot object with the PCA plot.

See also

Author

Fabricio Almeida-Silva

Examples

data(zma.se)
plot_PCA(zma.se, log_trans = TRUE)