Merge pull request #422 from ritchie46/trussGenerator

Truss generator preprocessor

Author: brookshsmith

.coverage

@@ -89,4 +89,5 @@ MANIFEST
 build/
 .ipynb_checkpoints/
 
-dev/
+dev/
+.coverage

.gitignore

@@ -1,3 +1,4 @@
 from anastruct.fem.system import SystemElements
 from anastruct.fem.util.load import LoadCase, LoadCombination
+from anastruct.preprocess import truss
 from anastruct.vertex import Vertex

anastruct/__init__.py

@@ -2363,6 +2363,6 @@ def _negative_index_to_id(idx: int, collection: Collection[int]) -> int:
             idx = int(idx)
         else:
             raise TypeError("Node or element id must be an integer")
-    if idx > 0:
+    if idx >= 0:
         return idx
     return max(collection) + (idx + 1)

anastruct/fem/system.py

@@ -203,6 +203,48 @@ def det_node_ids(
     return node_ids[0], node_ids[1]
 
 
+def add_node(
+    system: "SystemElements", point: Vertex, node_id: Optional[int] = None
+) -> int:
+    """Add a node, optionally with a specific ID, without adding an element
+
+    Args:
+        system (SystemElements): System in which the nodes are located
+        point (Vertex): Location of the node
+        node_id (Optional[int], optional): node_id to assign to the node. Defaults to None,
+            which means to use the first available node_id automatically.
+
+    Raises:
+        FEMException: Raised when the location is already assigned to a different node id.
+        FEMException: Raised when the node id is already assigned to a different location.
+
+    Returns:
+        int: The node id of the added (or existing) node
+    """
+    if point in system._vertices:
+        if node_id is not None:
+            existing_node_id = system._vertices[point]
+            if existing_node_id != node_id:
+                raise FEMException(
+                    "Flawed inputs",
+                    f"Location {point} is already assigned to node id {existing_node_id}, "
+                    f"cannot assign to node id {node_id}.",
+                )
+        return existing_node_id
+
+    if node_id is None:
+        node_id = max(system.node_map.keys(), default=0) + 1
+    elif node_id in system.node_map and system.node_map[node_id].vertex != point:
+        raise FEMException(
+            "Flawed inputs",
+            f"Node id {node_id} is already assigned to a different location.",
+        )
+
+    system._vertices[point] = node_id
+    system.node_map[node_id] = Node(node_id, vertex=point)
+    return node_id
+
+
 def support_check(system: "SystemElements", node_id: int) -> None:
     """Check if the node is a hinge