[英]Removing nodes from a Prefuse graph
我正在嘗試創建動態更新的Prefuse圖,其中定期添加和刪除節點。 我已經能夠很好地添加節點和邊,然后刪除它們,但是當我嘗試將邊添加到下一組節點時,我得到了例外。 有人知道從Prefuse圖中刪除節點有什么陷阱嗎? 或者,沒有人知道更好的與Prefuse圖動態交互的方法嗎?
(請注意,顯示正在良好地更新;在任何時候,顯示似乎都與圖的內容匹配。這並不是Prefuse Toolkit的復制品:動態添加節點和邊 )
代碼摘錄:
// Set up edge and node tables
Schema node_schema = new Schema();
Schema edge_schema = new Schema();
node_schema.addColumn("node_info", NodeInfo.class);
edge_schema.addColumn("source", int.class, 0);
edge_schema.addColumn("target", int.class, 0);
edge_schema.addColumn("edge_info", EdgeInfo.class);
graph_nodes = node_schema.instantiate();
graph_edges = edge_schema.instantiate();
...
// Set up visualization
graph = new Graph(graph_nodes, graph_edges, false);
vis_panel = new MyVisPanel(graph);
...
// Add nodes & edges
int new_node_1 = graph_nodes.addRow();
graph_nodes.set(new_node_1, "node_info", new NodeInfo());
int new_node_2 = graph_nodes.addRow();
graph_nodes.set(new_node_2, "node_info", new NodeInfo());
int new_edge = graph_edges.addRow();
graph_edges.set(new_edge, "target", new_node_1);
graph_edges.set(new_edge, "source", new_node_2);
...
// Remove nodes
TupleSet nodes = graph.getNodes();
Iterator iter = nodes.tuples(my_predicate);
while(iter.hasNext())
{
int row_to_delete = ((Tuple) iter.next()).getRow();
if(graph.removeNode(row_to_delete))
{
System.out.println("Removed row " + row_to_delete);
}
}
...
// Add nodes & edges again
int new_node_1 = graph_nodes.addRow();
graph_nodes.set(new_node_1, "node_info", new NodeInfo());
int new_node_2 = graph_nodes.addRow();
graph_nodes.set(new_node_2, "node_info", new NodeInfo());
int new_edge = graph_edges.addRow(); // <<-- Exception is thrown here
graph_edges.set(new_edge, "target", new_node_1);
graph_edges.set(new_edge, "source", new_node_2);
我得到的異常是:
java.lang.IllegalArgumentException: Row index out of bounds: -1
at prefuse.data.column.IntColumn.getInt(Unknown Source)
at prefuse.data.Table.getInt(Unknown Source)
at prefuse.data.Graph.updateDegrees(Unknown Source)
at prefuse.data.Graph.updateDegrees(Unknown Source)
at prefuse.data.Graph$Listener.tableChanged(Unknown Source)
at prefuse.data.Table.fireTableEvent(Unknown Source)
at prefuse.data.Table.addRow(Unknown Source)
at my_pkg.addSomeNodesFunction(my_code.java:99)
我沒有使用標准的Graph.addNode()和addEdge()方法,因為用這種方法設置邊緣信息似乎更加困難。 (如果有更好的方法,請告訴我!)刪除成功,因為在刪除節點之后,graph.getNodeCount()和graph.getEdgeCount()返回的數字較小。
有任何想法嗎?
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.