ertk.utils.flat_to_inst

ertk.utils.flat_to_inst(x: ndarray, slices: ndarray | List[int]) → ndarray

Takes a concatenated 2D data array and converts it to either a contiguous 2D/3D array or a variable-length 3D array, with one feature vector/matrix per instance.

Parameters:

x: numpy.ndarray

Contiguous 2D array containing concatenated instance data.

slices: list or numpy.ndarray

Array containing lengths of sequences in x corresponding to instance data.

Returns:

inst: numpy.ndarray

Instance array, which is either contiguous 2D, contiguous 3D or an array of 2D arrays with varying lengths. It should be the case that inst[i] == x[s : s + slices[i]], where s = sum(slices[:i]).