[Constraints] Created VertexConstraint

src/jax_fdm/constraints/__init__.py

@@ -2,6 +2,7 @@
 from .node import *  # noqa F403
 from .edge import *  # noqa F403
 from .network import *  # noqa F403
+from .vertex import *  # noqa F403
 
 
 __all__ = [name for name in dir() if not name.startswith('_')]

src/jax_fdm/constraints/vertex/__init__.py

@@ -0,0 +1,5 @@
+from .vertex import *  # noqa F403
+from .coordinates import *  # noqa F403
+
+
+__all__ = [name for name in dir() if not name.startswith('_')]

src/jax_fdm/constraints/vertex/coordinates.py

@@ -0,0 +1,37 @@
+from jax_fdm.constraints.vertex import VertexConstraint
+
+
+class VertexXCoordinateConstraint(VertexConstraint):
+    """
+    Constraint the X coordinate of a vertex between a lower and an upper bound.
+    """
+    @staticmethod
+    def constraint(eqstate, index):
+        """
+        Returns the X coordinate of a vertex from an equilibrium state.
+        """
+        return eqstate.xyz[index, :1]
+
+
+class VertexYCoordinateConstraint(VertexConstraint):
+    """
+    Constraint the Y coordinate of a vertex between a lower and an upper bound.
+    """
+    @staticmethod
+    def constraint(eqstate, index):
+        """
+        Returns the Y coordinate of a vertex from an equilibrium state.
+        """
+        return eqstate.xyz[index, 1:2]
+
+
+class VertexZCoordinateConstraint(VertexConstraint):
+    """
+    Constraint the Z coordinate of a vertex between a lower and an upper bound.
+    """
+    @staticmethod
+    def constraint(eqstate, index):
+        """
+        Returns the Z coordinate of a vertex from an equilibrium state.
+        """
+        return eqstate.xyz[index, 2]

src/jax_fdm/constraints/vertex/vertex.py

@@ -0,0 +1,15 @@
+from jax_fdm.constraints import Constraint
+
+
+class VertexConstraint(Constraint):
+    """
+    Base class for all constraints that pertain to a vertex in a mesh.
+    """
+    def index_from_model(self, model, structure):
+        """
+        The index of the node in a structure.
+        """
+        try:
+            return structure.vertex_index[self.key]
+        except TypeError:
+            return tuple([structure.vertex_index[k] for k in self.key])