Added shell

lbmweights/shell.py

+import numpy as np
+from .utils.mylog import logger
+
+
+class Shell:
+    def __init__(self, velocities):
+        self._weight = None
+        self._c_s_sq = None
+        self.shell = abs(velocities[0]**2).sum()
+        self.type = tuple(np.sort(abs(velocities[0])))
+        self.size = len(velocities)
+        self.velocities = velocities
+
+    def __repr__(self):
+        repr_string = "Shell: {} - Type: {} - Amount of velocities: {}".format(self.shell, self.type, self.size)
+        if self._weight is not None:
+            repr_string += " - Weight: {}".format(self.weight)
+        return repr_string
+
+    @property
+    def weight(self):
+        if self._weight is None:
+            logger.warning("Weight of shell uninitialized. Calculate it first")
+        return self._weight
+
+    def set_weight(self, c_s_sq, weight):
+        self._c_s_sq = c_s_sq
+        self._weight = weight