我目前正在开发一种工具，用于使用图和Java JUNG图可视化库来可视化宏基因组学数据。
当显示大约1000个节点时，我会遇到一个延迟，这是通过移动摄像机或拖动某些节点来实现的。
有没有可以用来改善这种情况的技巧？
我读了一些关于将窗口分为几部分的内容，并且只适用于正在显示的面板的一部分，但是我不明白这一点。
谢谢。
最佳答案
该问题可能被认为过于笼统，因为优化的自由度太多了。并且存在至少相关的问题（Improve the rendering of a JUNG graph ，JUNG cannot display large graphs?或其他），如果不是重复的话。
但是，我会在这里尝试回答：
通常，使用JUNG，您可以轻松地用几行代码创建一个漂亮的图形，并具有令人印象深刻的默认功能（交互）和许多功能。在这方面，JUNG并非主要针对绘制具有1000个顶点的图形。相反，它的目的是很好地绘制具有数十个（或几百个）顶点和边的图形。
（实际上，从理论上以信息可视化的角度来看，绘制具有> 1000个顶点的图形几乎毫无意义。至少，如果没有过度的缩放和平移，您将无法从图形中直观地提取任何信息。 ）
当您要绘制具有许多顶点和许多边的图形时，可以使用一些选项来提高性能。 （您没有说出边的数量。在很多情况下，这是最昂贵的东西！）。
根据我的经验，提高渲染性能的最重要的事情就是...
禁用抗锯齿！
严重的是，这确实很昂贵。在荣格，这可以做到
visualizationViewer.getRenderingHints().remove(
RenderingHints.KEY_ANTIALIASING)
除此之外，还有许多提高性能的选项，但是，当然，它们全都取决于您要牺牲哪种视觉功能。下面的示例显示了一个具有2500个顶点和5000个边的图形。默认情况下，它非常慢。
improvePerformance方法包含有关如何使可视化更快的几个选项。即使仅禁用抗锯齿功能，在我的机器（速度较慢）上，性能还是可以接受的。根据评论进行编辑/扩展：
import java.awt.Dimension;
import java.awt.RenderingHints;
import java.awt.Stroke;
import java.awt.geom.Point2D;
import java.util.Random;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
import org.apache.commons.collections15.Predicate;
import edu.uci.ics.jung.algorithms.layout.FRLayout;
import edu.uci.ics.jung.algorithms.layout.Layout;
import edu.uci.ics.jung.graph.DirectedSparseGraph;
import edu.uci.ics.jung.graph.Graph;
import edu.uci.ics.jung.graph.util.Context;
import edu.uci.ics.jung.graph.util.Pair;
import edu.uci.ics.jung.visualization.Layer;
import edu.uci.ics.jung.visualization.RenderContext;
import edu.uci.ics.jung.visualization.VisualizationViewer;
import edu.uci.ics.jung.visualization.control.DefaultModalGraphMouse;
import edu.uci.ics.jung.visualization.decorators.EdgeShape;
import edu.uci.ics.jung.visualization.renderers.BasicEdgeRenderer;
import edu.uci.ics.jung.visualization.transform.shape.GraphicsDecorator;
public class JungPerformance
{
public static void main(String[] args)
{
SwingUtilities.invokeLater(new Runnable()
{
@Override
public void run()
{
createAndShowGUI();
}
});
}
private static void createAndShowGUI()
{
JFrame f = new JFrame();
f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Graph<String, String> g = createGraph();
Dimension size = new Dimension(800,800);
VisualizationViewer<String, String> vv =
new VisualizationViewer<String, String>(
new FRLayout<String, String>(g, size));
DefaultModalGraphMouse<String, Double> graphMouse =
new DefaultModalGraphMouse<String, Double>();
vv.setGraphMouse(graphMouse);
improvePerformance(vv);
f.getContentPane().add(vv);
f.setSize(size);
f.setLocationRelativeTo(null);
f.setVisible(true);
}
// This method summarizes several options for improving the painting
// performance. Enable or disable them depending on which visual features
// you want to sacrifice for the higher performance.
private static <V, E> void improvePerformance(
VisualizationViewer<V, E> vv)
{
// Probably the most important step for the pure rendering performance:
// Disable anti-aliasing
vv.getRenderingHints().remove(RenderingHints.KEY_ANTIALIASING);
// Skip vertices that are not inside the visible area.
doNotPaintInvisibleVertices(vv);
// May be helpful for performance in general, but not appropriate
// when there are multiple edges between a pair of nodes: Draw
// the edges not as curves, but as straight lines:
vv.getRenderContext().setEdgeShapeTransformer(new EdgeShape.Line<V,E>());
// May be helpful for painting performance: Omit the arrow heads
// of directed edges
Predicate<Context<Graph<V, E>, E>> edgeArrowPredicate =
new Predicate<Context<Graph<V,E>,E>>()
{
@Override
public boolean evaluate(Context<Graph<V, E>, E> arg0)
{
return false;
}
};
vv.getRenderContext().setEdgeArrowPredicate(edgeArrowPredicate);
}
// Skip all vertices that are not in the visible area.
// NOTE: See notes at the end of this method!
private static <V, E> void doNotPaintInvisibleVertices(
VisualizationViewer<V, E> vv)
{
Predicate<Context<Graph<V, E>, V>> vertexIncludePredicate =
new Predicate<Context<Graph<V,E>,V>>()
{
Dimension size = new Dimension();
@Override
public boolean evaluate(Context<Graph<V, E>, V> c)
{
vv.getSize(size);
Point2D point = vv.getGraphLayout().transform(c.element);
Point2D transformed =
vv.getRenderContext().getMultiLayerTransformer()
.transform(point);
if (transformed.getX() < 0 || transformed.getX() > size.width)
{
return false;
}
if (transformed.getY() < 0 || transformed.getY() > size.height)
{
return false;
}
return true;
}
};
vv.getRenderContext().setVertexIncludePredicate(vertexIncludePredicate);
// NOTE: By default, edges will NOT be included in the visualization
// when ONE of their vertices is NOT included in the visualization.
// This may look a bit odd when zooming and panning over the graph.
// Calling the following method will cause the edges to be skipped
// ONLY when BOTH their vertices are NOT included in the visualization,
// which may look nicer and more intuitive
doPaintEdgesAtLeastOneVertexIsVisible(vv);
}
// See note at end of "doNotPaintInvisibleVertices"
private static <V, E> void doPaintEdgesAtLeastOneVertexIsVisible(
VisualizationViewer<V, E> vv)
{
vv.getRenderer().setEdgeRenderer(new BasicEdgeRenderer<V, E>()
{
@Override
public void paintEdge(RenderContext<V,E> rc, Layout<V, E> layout, E e)
{
GraphicsDecorator g2d = rc.getGraphicsContext();
Graph<V,E> graph = layout.getGraph();
if (!rc.getEdgeIncludePredicate().evaluate(
Context.<Graph<V,E>,E>getInstance(graph,e)))
return;
Pair<V> endpoints = graph.getEndpoints(e);
V v1 = endpoints.getFirst();
V v2 = endpoints.getSecond();
if (!rc.getVertexIncludePredicate().evaluate(
Context.<Graph<V,E>,V>getInstance(graph,v1)) &&
!rc.getVertexIncludePredicate().evaluate(
Context.<Graph<V,E>,V>getInstance(graph,v2)))
return;
Stroke new_stroke = rc.getEdgeStrokeTransformer().transform(e);
Stroke old_stroke = g2d.getStroke();
if (new_stroke != null)
g2d.setStroke(new_stroke);
drawSimpleEdge(rc, layout, e);
// restore paint and stroke
if (new_stroke != null)
g2d.setStroke(old_stroke);
}
});
}
public static Graph<String, String> createGraph()
{
Random random = new Random(0);
int numVertices = 2500;
int numEdges = 5000;
Graph<String, String> g = new DirectedSparseGraph<String, String>();
for (int i=0; i<numVertices; i++)
{
g.addVertex("v"+i);
}
for (int i=0; i<numEdges; i++)
{
int v0 = random.nextInt(numVertices);
int v1 = random.nextInt(numVertices);
g.addEdge("e"+i, "v"+v0, "v"+v1);
}
return g;
}
}
关于java - JUNG-大图可视化，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/37740057/