Question

I want to show users a heatmap with 10000 * 400 tiles. Current state in my program is that I have a class which is a JComponent. In this JComponent, I have instances of Image for the tiles. If I had a 300 * 300 matrix, the program uses between 800 and 1000 MB ram. This is too much.

What can I do else or has someone a control which can show such a big heatmap?

Today I have tested JHeatChart, which creates a BufferedImage. There the size for a 10000 * 400 matrix is under 400 MB, but the class needs over 15 Minutes to create it. This is too long.

Has anybody some idee or knows an control which can handle the data?

Answer 1

Since this will be a map, you do not need to create a component for each tile. many of them can be re-used. What you want to do is during initialization of the app, create a map of all possible components, and then on each tile pass a reference to that component.

Here would be an example.

public class HeatMap{

private static List<JComponent> tiles = new ArrayList<JComponent>();    
private List<JComponent> heatmap = new ArrayList<JComponent>();
private Random rand = new Random();

static{
    tiles.add(new JLabel("Cold"));
    tiles.add(new JLabel("Hot"));
    tiles.add(new JLabel("Warm"));
}

public HeatMap(){
    for(int i=0; i<10000; i++){
        for(int j=0; j<400; j++){
                heatmap.add(tiles.get(rand.nextInt(3)));            
        }
    }
}
}

In the above case we only have to create 3 tiles, the rest are references to those. This type of approach should help reduce your memory usage.