pointpats.j¶
- pointpats.j(coordinates, support=None, distances=None, metric='euclidean', hull=None, edge_correction=None, truncate=True)[source]¶
Ripely’s J function
The so-called “spatial hazard” function, this is a function relating the F and G functions.
- Parameters:
- coordinatesnumpy.ndarray, (n,2)
input coordinates to function
- supporttuple of length 1, 2, or 3, int, or numpy.ndarray
tuple, encoding (stop,), (start, stop), or (start, stop, num) int, encoding number of equally-spaced intervals numpy.ndarray, used directly within numpy.histogram
- distances: tuple of numpy.ndarray
precomputed distances to use to evaluate the j function. The first must be of shape (n,n) or (n,) and is used in the g function. the second must be of shape (n,p) or (p,) (with p possibly equal to n) used in the f function.
- metric: str or callable
distance metric to use when building search tree
- hull: bounding box, scipy.spatial.ConvexHull, shapely.geometry.Polygon
the hull used to construct a random sample pattern for the f function.
- edge_correction: bool or str
whether or not to conduct edge correction. Not yet implemented.
- truncate: bool (default: True)
whether or not to truncate the results when the F function reaches one. If the F function is one but the G function is less than one, this function will return numpy.nan values.
- Returns:
- a tuple containing the support values used to evalute the function
- and the values of the function at each distance value in the support.