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Instance.javaAPI DocAndroid 5.1 API3581Thu Mar 12 22:22:10 GMT 2015android.gesture

Instance

public class Instance extends Object
An instance represents a sample if the label is available or a query if the label is null.

Fields Summary
private static final int
SEQUENCE_SAMPLE_SIZE
private static final int
PATCH_SAMPLE_SIZE
private static final float[]
ORIENTATIONS
final float[]
vector
final String
label
final long
id
Constructors Summary
private Instance(long id, float[] sample, String sampleName)


           
        this.id = id;
        vector = sample;
        label = sampleName;
Methods Summary
static android.gesture.InstancecreateInstance(int sequenceType, int orientationType, Gesture gesture, java.lang.String label)
create a learning instance for a single stroke gesture

param
gesture
param
label
return
the instance

        float[] pts;
        Instance instance;
        if (sequenceType == GestureStore.SEQUENCE_SENSITIVE) {
            pts = temporalSampler(orientationType, gesture);
            instance = new Instance(gesture.getID(), pts, label);
            instance.normalize();
        } else {
            pts = spatialSampler(gesture);
            instance = new Instance(gesture.getID(), pts, label);
        }
        return instance;
private voidnormalize()

        float[] sample = vector;
        float sum = 0;

        int size = sample.length;
        for (int i = 0; i < size; i++) {
            sum += sample[i] * sample[i];
        }

        float magnitude = (float)Math.sqrt(sum);
        for (int i = 0; i < size; i++) {
            sample[i] /= magnitude;
        }
private static float[]spatialSampler(Gesture gesture)

        return GestureUtils.spatialSampling(gesture, PATCH_SAMPLE_SIZE, false);
private static float[]temporalSampler(int orientationType, Gesture gesture)

        float[] pts = GestureUtils.temporalSampling(gesture.getStrokes().get(0),
                SEQUENCE_SAMPLE_SIZE);
        float[] center = GestureUtils.computeCentroid(pts);
        float orientation = (float)Math.atan2(pts[1] - center[1], pts[0] - center[0]);

        float adjustment = -orientation;
        if (orientationType != GestureStore.ORIENTATION_INVARIANT) {
            int count = ORIENTATIONS.length;
            for (int i = 0; i < count; i++) {
                float delta = ORIENTATIONS[i] - orientation;
                if (Math.abs(delta) < Math.abs(adjustment)) {
                    adjustment = delta;
                }
            }
        }

        GestureUtils.translate(pts, -center[0], -center[1]);
        GestureUtils.rotate(pts, adjustment);

        return pts;