"""
This module implements a function to understand chaincodes from HELIO.
"""
import numpy as np
__all__ = ["Chaincode"]
[docs]
class Chaincode(np.ndarray):
"""
A tool to infer some information from chaincodes produced by HELIO Feature
Catalogue or Heliophysics Events Knowledgebase.
Parameters
----------
origin : `numpy.ndarray`, `list`
The 2 points of the origin of the chaincode.
chaincode : `str`
A list of the numbers (0-7) that indicate the path of the chaincode.
0 moves horizontally to the left and the rest follows anticlockwise.
xdelta : `float`, optional
The scale to convert between pixels and flat coordinates. Defaults to 1.0.
ydelta : `float`, optional
The scale to convert between pixels and flat coordinates. Defaults to 1.0
Returns
-------
`numpy.ndarray`
An array containing all the x and y coordinates of the chaincode
e.g., ``[[x0, x1, x2, ..., xn], [y0 ,y1, y2, ..., yn]]``.
Examples
--------
>>> from sunpy.net.helio.chaincode import Chaincode
>>> cc = Chaincode([-88, 812], "44464655567670006011212222324",
... xdelta=2.629, ydelta=2.629)
>>> fig = plt.figure() # doctest: +SKIP
>>> ax = fig.add_subplot(111) # doctest: +SKIP
>>> x,y = zip(cc.coordinates) # doctest: +SKIP
>>> ax.plot(x[0], y[0], 'go-') # doctest: +SKIP
>>> fig.show() # doctest: +SKIP
"""
def __new__(cls, origin, chaincode, **kwargs):
if isinstance(origin, list):
obj = np.asarray(origin).view(cls)
elif isinstance(origin, np.ndarray):
obj = origin.view(cls)
else:
raise TypeError('Invalid input')
return obj
def __init__(self, origin, chaincode, xdelta=1, ydelta=1):
x_steps = [-1, -1, 0, 1, 1, 1, 0, -1]
y_steps = [0, -1, -1, -1, 0, 1, 1, 1]
self.coordinates = np.ndarray((2, len(chaincode) + 1))
self.coordinates[:, 0] = origin
if chaincode.isdigit():
for index, step in enumerate(chaincode):
self.coordinates[:, index + 1] = self.coordinates[:, index] + \
[[x_steps[int(step)] * xdelta,
y_steps[int(step)] * ydelta]]
[docs]
def matchend(self, end):
return np.all(np.equal(self.coordinates[:, -1], np.asarray(end)))
[docs]
def matchany(self, coordinates, index):
return np.all(
np.allclose(self.coordinates[:, index], np.asarray(coordinates))
)
[docs]
def boundingbox(self):
"""
Extract the coordinates of the chaincode.
Returns in the form of ``[[x0, x1], [y0, y1]]``.
"""
bb = np.zeros((2, 2))
bb[:, 0] = self.coordinates.min(1)
bb[:, 1] = self.coordinates.max(1)
return bb
[docs]
def area(self):
raise NotImplementedError
[docs]
def length(self):
raise NotImplementedError
[docs]
def sub_boundingbox(self, xedge=None, yedge=None):
"""
Extract the x or y boundaries of the chaincode from a defined limits
``xedge`` or ``yedge``.
Parameters
----------
xedge : list, optional
A list of two values to check.
yedge : list, optional
A list of two values to check.
"""
if xedge is not None:
edge = xedge
IndexMask = 0
IndexValue = 1
elif yedge is not None:
edge = yedge
IndexMask = 1
IndexValue = 0
else:
raise ValueError("Please input either `xedge` or `yedge`")
mask = (self.coordinates[IndexMask, :] >= edge[0]) & (self.coordinates[IndexMask, :] <= edge[1])
mx = np.ma.masked_array(self.coordinates[IndexValue, :], mask=(~mask))
return [mx.min(), mx.max()]
