fix: adding datatypes module

LoopStructural/datatypes/_surface.py

@@ -0,0 +1,18 @@
+from dataclasses import dataclass
+from typing import Optional, Union
+import numpy as np
+
+
+@dataclass
+class Surface:
+    vertices: np.ndarray
+    triangles: np.ndarray
+    normals: np.ndarray
+    name: str
+    values: Optional[np.ndarray] = None
+
+    @property
+    def pyvista(self):
+        import pyvista as pv
+
+        return pv.pv.PolyData.from_regular_faces(self.vertices, self.triangles)

LoopStructural/datatypes/_value.py

@@ -0,0 +1,7 @@
+from dataclasses import dataclass
+
+
+@dataclass
+class Value:
+
+

LoopStructural/datatypes/_value_set.py

@@ -0,0 +1,6 @@
+# import numpy as np
+
+
+# class ValueSet:
+#     def __init__(self, values: np.ndarray):
+#         self.values = values