This unexported helper function is used to identify the shape in the plane_shape()
function's scaled difference ("sdiff") method.
get_shapes(input_data, window_size)
A vector with the shapes identified. Each element of the vector will include a shape, which is a cluster of categorical differences (of the same size as the specified "window_size") collapsed with ";" (e.g., c("decrease;stable;stable;stable","stable;stable;stable;increase","stable;stable;increase;increase")
).
A data frame containing at least two columns, one of which must be named "value" with the value assessed and another named "dates" with the date for the observed data
The number of of categorical differences used to define the shape