ColorArray Limitation for Denstream Cluster id assignment, [cluster_id 51 problem][POSSIBLE BUG]

[celikmustafa89]

I am using denstream algorithm for clustering. The algorithm creates clusters, assigns cluster_ids and colors for each cluster up to 52 clusters[0,1,2….51]. However, after cluster-52 it does not work properly. It assigns id 51 to rest of clusters which should be 52,53,54,55,56… etc. I have traced the code and got followings; Denstream algorithm uses setClusterIDs(Clustering clustering) methods which is implemented in moa/clusterers/macro/AbstractMacroClusterer.java class. In this method, there is following code block which uses ColorArray.java class for assigning ids and colors for clusters.

                // check if there are 2 clusters with the same color (same id, could
        // appear after a split);
        double freeID = 0;
        List<Double> reservedIDs = new Vector<Double>();
        reservedIDs.addAll(countIDs.keySet());
        for (Map.Entry<Double, Integer> entry : countIDs.entrySet()) {
            if (entry.getValue() > 1 || entry.getKey() == -1) {
                // find first free id, search all the clusters which has the
                // same id and replace the ids with free ids. One cluster can
                // keep its id
                int to = entry.getValue();
                if (entry.getKey() != -1)
                    to--;

                for (int i = 0; i < to; i++) {
                    while (reservedIDs.contains(freeID)
                            && freeID < ColorArray.getNumColors())
                        freeID += 1.0;
                    for (int c = clustering.size() - 1; c >= 0; c--)
                        if (clustering.get(c).getId() == entry.getKey()) {
                            clustering.get(c).setId(freeID);
                            reservedIDs.add(freeID);
                            break;
                        }
                }
            }
        }

In this code block, method uses ColorArray.mVisibleColors.length for assigning id’s and colors. This array has only 52 different colors and it limits the cluster_id assignment. After 52 cluster, it assigns same cluster_id(51) for all clusters. ColorArray has those colors on code-block-2. I have added more colors to this array and it solved the problem. Here is my issue on google_group. And my pull request. Can you review it or inform me for further steps?

// CODE-BLOCK-2
public class ColorArray {
    public static ColorObject[] mVisibleColors = {
            new ColorObject("blue", new Color(0x0000ff)),
            new ColorObject("blueviolet", new Color(0x8a2be2)),
            new ColorObject("brown", new Color(0xa52a2a)),
            new ColorObject("burlywood", new Color(0xdeb887)),
            new ColorObject("cadetblue", new Color(0x5f9ea0)),
            //new ColorObject("chartreuse", new Color(0x7fff00)),
            new ColorObject("chocolate", new Color(0xd2691e)),
            new ColorObject("coral", new Color(0xff7f50)),
            new ColorObject("cornflowerblue", new Color(0x6495ed)),
            new ColorObject("crimson", new Color(0xdc143c)),
            new ColorObject("cyan", new Color(0x00ffff)),
            new ColorObject("darkblue", new Color(0x00008b)),
            new ColorObject("darkcyan", new Color(0x008b8b)),
            new ColorObject("darkgoldenrod", new Color(0xb8860b)),
            new ColorObject("darkgreen", new Color(0x006400)),
            new ColorObject("darkkhaki", new Color(0xbdb76b)),
            new ColorObject("darkmagenta", new Color(0x8b008b)),
            new ColorObject("darkolivegreen", new Color(0x556b2f)),
            new ColorObject("darkorange", new Color(0xff8c00)),
            // new ColorObject("darkorchid", new Color(0x9932cc)),
            new ColorObject("darkred", new Color(0x8b0000)),
            new ColorObject("darksalmon", new Color(0xe9967a)),
            new ColorObject("darkseagreen", new Color(0x8fbc8f)),
            new ColorObject("darkslateblue", new Color(0x483d8b)),
            new ColorObject("darkslategray", new Color(0x2f4f4f)),
            // new ColorObject("darkturquoise", new Color(0x00ced1)),
            new ColorObject("darkviolet", new Color(0x9400d3)),
            new ColorObject("deeppink", new Color(0xff1493)),
            new ColorObject("deepskyblue", new Color(0x00bfff)),
            // new ColorObject("dodgerblue", new Color(0x1e90ff)),
            new ColorObject("firebrick", new Color(0xb22222)),
            new ColorObject("forestgreen", new Color(0x228b22)),
            new ColorObject("fuchsia", new Color(0xff00ff)),
            new ColorObject("gold", new Color(0xffd700)),
            new ColorObject("goldenrod", new Color(0xdaa520)),
            //new ColorObject("green", new Color(0x008000)),
            new ColorObject("greenyellow", new Color(0xadff2f)),
            new ColorObject("hotpink", new Color(0xff69b4)),
            new ColorObject("indianred", new Color(0xcd5c5c)),
            new ColorObject("indigo", new Color(0x4b0082)),
            //new ColorObject("lawngreen", new Color(0x7cfc00)),
            // new ColorObject("lime", new Color(0x00ff00)),
            // new ColorObject("limegreen", new Color(0x32cd32)),
            new ColorObject("magenta", new Color(0xff00ff)),
            new ColorObject("maroon", new Color(0x800000)),
            new ColorObject("olive", new Color(0x808000)),
            new ColorObject("orange", new Color(0xffa500)),
            new ColorObject("orangered", new Color(0xff4500)),
            new ColorObject("pink", new Color(0xffc0cb)),
            new ColorObject("powderblue", new Color(0xb0e0e6)),
            new ColorObject("purple", new Color(0x800080)),
            new ColorObject("red", new Color(0xff0000)),
            new ColorObject("royalblue", new Color(0x4169e1)),
            new ColorObject("saddlebrown", new Color(0x8b4513)),
            new ColorObject("salmon", new Color(0xfa8072)),
            new ColorObject("seagreen", new Color(0x2e8b57)),
            new ColorObject("skyblue", new Color(0x87ceeb)),
            new ColorObject("slateblue", new Color(0x6a5acd)),
            new ColorObject("tomato", new Color(0xff6347)),
            new ColorObject("violet", new Color(0xee82ee)) };

    public static Color getColor(int i) {
        Color res;
        try {
            res = mVisibleColors[i].getColor();
        } catch (ArrayIndexOutOfBoundsException e) {
            return Color.BLACK;
        }
        return res;
    }

    public static String getName(int i) {
        String res;
        try {
            res = mVisibleColors[i].getName();
        } catch (ArrayIndexOutOfBoundsException e) {
            throw e;
        }
        return res;
    }

    public static double getNumColors() {
        return mVisibleColors.length;
    }
}

[celikmustafa89]

this bug is fixed, I am closing the issue