This function transforms geometric structures by translating, scaling and/or rotating them.

Usage

GeomTrans(x, y = NULL, trans = 0, scale = 1, theta = 0)

Value

The function invisibly returns a list of the coordinates for the transformed shape(s).

Arguments

x, y

vectors containing the coordinates of the vertices of the polygon
, which has to be transformed. The coordinates can be passed in a plotting structure (a list with x and y components), a two-column matrix, .... See xy.coords.

trans

a vector of two values for the translation in x-, resp. y-direction. If only one value is supplied it will be recycled.

scale

a vector of two values for the scaling factor in x-, resp. y-direction. If only one value is supplied it will be recycled.

theta

angle of the rotation in radians starting from 3 o'clock counterclockwise.