Compute shape of a whole track

Author: AntSimi

src/py_eddy_tracker/observations/tracking.py

@@ -28,7 +28,7 @@
 
 from .. import VAR_DESCR_inv
 from ..generic import build_index, cumsum_by_track, distance, split_line, wrap_longitude
-from ..poly import create_vertice_from_2darray, polygon_overlap
+from ..poly import create_vertice_from_2darray, merge, polygon_overlap
 from .observation import EddiesObservations
 
 logger = logging.getLogger("pet")
@@ -489,6 +489,43 @@ def extract_with_mask(
                 new.track = id_translate[new.track]
         return new
 
+    def shape_polygon(self, intern=False):
+        """
+        Get polygons which enclosed each track
+
+        :param bool intern: If True use speed contour instead of effective contour
+        :rtype: list(array, array)
+        """
+        xname, yname = self.intern(intern)
+        return [merge(track[xname], track[yname]) for track in self.iter_track()]
+
+    def display_shape(self, ax, ref=None, intern=False, **kwargs):
+        """
+        This function will draw shape of each track
+
+        :param matplotlib.axes.Axes ax: ax where drawed
+        :param float,int ref: if defined all coordinates will be wrapped with ref like west boundary
+        :param bool intern: If True use speed contour instead of effective contour
+        :param dict kwargs: keyword arguments for Axes.plot
+        :return: matplotlib mappable
+        """
+        if "label" in kwargs:
+            kwargs["label"] = self.format_label(kwargs["label"])
+        if len(self) == 0:
+            x, y = [], []
+        else:
+            polygons = self.shape_polygon(intern)
+            x, y = list(), list()
+            for p_ in polygons:
+                x.append((nan,))
+                y.append((nan,))
+                x.append(p_[0])
+                y.append(p_[1])
+            x, y = concatenate(x), concatenate(y)
+            if ref is not None:
+                x, y = wrap_longitude(x, y, ref, cut=True)
+        return ax.plot(x, y, **kwargs)
+
     def plot(self, ax, ref=None, **kwargs):
         """
         This function will draw path of each track

src/py_eddy_tracker/poly.py

@@ -5,7 +5,7 @@
 
 from numba import njit, prange
 from numba import types as numba_types
-from numpy import array, concatenate, empty, ones, pi, where
+from numpy import array, concatenate, empty, nan, ones, pi, where
 from numpy.linalg import lstsq
 from Polygon import Polygon
 
@@ -379,6 +379,33 @@ def get_wrap_vertice(x0, y0, x1, y1, i):
     return create_vertice(x0_, y0[i]), create_vertice(x1_, y1[i])
 
 
+def merge(x, y):
+    """
+    Merge all polygon of the list
+
+    :param array x: 2D array for a list of polygon
+    :param array y: 2D array for a list of polygon
+    :return: Polygons which enclosed all
+    :rtype: array, array
+    """
+    nb = x.shape[0]
+    p = None
+    for i in range(nb):
+        p_ = Polygon(create_vertice(x[i], y[i]))
+        if p is None:
+            p = p_
+        else:
+            p += p_
+    x, y = list(), list()
+    for p_ in p:
+        p_ = array(p_).T
+        x.append((nan,))
+        y.append((nan,))
+        x.append(p_[0])
+        y.append(p_[1])
+    return concatenate(x), concatenate(y)
+
+
 def vertice_overlap(x0, y0, x1, y1, minimal_area=False):
     r"""
     Return percent of overlap for each item.