Extract Data Matrix

Retrieves the data matrix component from various object types in the package. This function provides a consistent interface for accessing the underlying data regardless of the specific object structure.

Usage

xdata(x, ...)

# S3 method for class 'multidesign'
xdata(x, ...)

Arguments

x

The object containing the data matrix

...

Additional arguments passed to methods: * For hyperdesign objects: 'block' parameter to specify which block's data to return

Value

The data matrix component of the object, or a list of matrices for hyperdesign objects

Details

The function behaves differently depending on the class of the input object: * For multidesign objects: Returns the data matrix component * For hyperdesign objects: Returns a list of data matrices, one for each block (or a single matrix if a specific block is requested) * For multiframe objects: Returns the combined data from all observations

See also

design for extracting design information, column_design for extracting column metadata

Examples

# With a multidesign object
X <- matrix(rnorm(20*10), 20, 10)
Y <- data.frame(group = rep(letters[1:4], each=5))
mds <- multidesign(X, Y)
X_data <- xdata(mds)  # Returns the original matrix X

# With a hyperdesign object
d1 <- multidesign(matrix(rnorm(10*5), 10, 5), data.frame(subject=rep(1,10)))
d2 <- multidesign(matrix(rnorm(10*5), 10, 5), data.frame(subject=rep(2,10)))
hd <- hyperdesign(list(d1, d2))
all_data <- xdata(hd)  # Returns list of matrices
block1_data <- xdata(hd, block=1)  # Returns just the first block's matrix