Apply transformation to coordinates

Apply a transformation (scale, rotation, translation) to shape coordinates.

Usage

get_transformed(x, ..., .cols = NULL, .ldk_col = NULL)

Arguments

x

A matrix (nx2), list of matrices, or tibble with coo columns.

...

Additional arguments (reserved for future use).

.cols

Column name(s) to process when x is a tibble. If NULL, automatically detects columns containing coo columns.

.ldk_col

Character. Name of landmark column. If NULL, uses colname_ldk.

transform

A list with elements scale, rotation, and translation, typically from get_transform().

Value

• If x is a single matrix: returns the transformed matrix

• If x is a list: returns a list of transformed matrices

• If x is a tibble: returns the tibble with transformed coo column(s)

Details

Applies transformation in order:

1. Scale (multiply coordinates by scale factor)

2. Rotate (by rotation angle in radians)

3. Translate (shift by translation vector)

Landmarks are transformed along with coordinates.

See also

get_transform() for extracting transformations

Examples

source <- matrix(c(0,0, 1,0, 1,1, 0,1), ncol=2, byrow=TRUE)
target <- source * 2  # Scaled by 2

# Extract transformation
transform <- get_transform(source, target)

# Apply to another shape
new_shape <- matrix(c(0,0, 2,0, 2,2), ncol=2, byrow=TRUE)
transformed <- get_transformed(new_shape, transform)