Example usage for org.apache.mahout.math Vector isDense

Introduction

In this page you can find the example usage for org.apache.mahout.math Vector isDense.

Prototype

boolean isDense();

Source Link

Document

true if this implementation should be considered dense -- that it explicitly represents every value

Usage

From source file:com.cloudera.science.ml.kmeans.parallel.CentersIndex.java

License:Open Source License

private BitSet index(Vector vec) {
    double[] prod = new double[projectionBits];
    if (vec.isDense()) {
        for (int i = 0; i < vec.size(); i++) {
            double v = vec.getQuick(i);
            if (v != 0.0) {
                for (int j = 0; j < projectionBits; j++) {
                    prod[j] += v * projection[i + j * dimensions];
                }//from  w w  w.java  2 s  . c  o m
            }
        }
    } else {
        Iterator<Vector.Element> iter = vec.iterateNonZero();
        while (iter.hasNext()) {
            Vector.Element e = iter.next();
            for (int j = 0; j < projectionBits; j++) {
                prod[j] = e.get() * projection[e.index() + j * dimensions];
            }
        }
    }
    BitSet bitset = new BitSet(projectionBits);
    for (int i = 0; i < projectionBits; i++) {
        if (prod[i] > 0.0) {
            bitset.set(i);
        }
    }
    return bitset;
}

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From source file:com.cloudera.science.ml.kmeans.parallel.CentersIndex.java

License:Open Source License

private static double dot(Vector vec, double[] p) {
    double dot = 0;
    if (vec.isDense()) {
        for (int i = 0; i < p.length; i++) {
            dot += vec.getQuick(i) * p[i];
        }/*from w  w  w  .jav  a2 s  . com*/
    } else {
        Iterator<Vector.Element> iter = vec.iterateNonZero();
        while (iter.hasNext()) {
            Vector.Element e = iter.next();
            dot += e.get() * p[e.index()];
        }
    }
    return dot;
}

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From source file:com.ikanow.infinit.e.processing.custom.utils.HadoopUtils.java

License:Open Source License

private static BasicDBList listFromMahoutVector(Vector vec, String prefix, BasicDBObject element) {
    if (vec instanceof NamedVector) {
        element.put(prefix + "Name", ((NamedVector) vec).getName());
    }/*from www  .j  a v  a2  s  .c  o m*/
    BasicDBList dbl2 = new BasicDBList();
    if (vec.isDense()) {
        int nSize = vec.size();
        dbl2.ensureCapacity(nSize);
        for (int i = 0; i < nSize; ++i) {
            dbl2.add(vec.getQuick(i));
        }
    } else { // sparse, write as a set in the format [{int:double}]
        Iterator<org.apache.mahout.math.Vector.Element> elIt = vec.iterateNonZero();
        while (elIt.hasNext()) {
            BasicDBObject el2 = new BasicDBObject();
            org.apache.mahout.math.Vector.Element el = elIt.next();
            el2.put("k", el.index());
            el2.put("v", el.get());
            dbl2.add(el2);
        }
    }
    return dbl2;
}

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From source file:edu.rosehulman.mahout.math.VectorWritable.java

License:Apache License

public static void writeVector(DataOutput out, Vector vector, boolean laxPrecision) throws IOException {
    boolean dense = vector.isDense();
    boolean sequential = vector.isSequentialAccess();
    boolean named = vector instanceof NamedVector;

    out.writeByte((dense ? FLAG_DENSE : 0) | (sequential ? FLAG_SEQUENTIAL : 0) | (named ? FLAG_NAMED : 0)
            | (laxPrecision ? FLAG_LAX_PRECISION : 0));

    Varint.writeUnsignedVarInt(vector.size(), out);
    if (dense) {//w  w w  .jav  a 2 s  .co  m
        for (Vector.Element element : vector.all()) {
            if (laxPrecision) {
                out.writeFloat((float) element.get());
            } else {
                out.writeDouble(element.get());
            }
        }
    } else {
        Varint.writeUnsignedVarInt(vector.getNumNonZeroElements(), out);
        Iterator<Element> iter = vector.nonZeroes().iterator();
        if (sequential) {
            int lastIndex = 0;
            while (iter.hasNext()) {
                Vector.Element element = iter.next();
                if (element.get() == 0) {
                    continue;
                }
                int thisIndex = element.index();
                // Delta-code indices:
                Varint.writeUnsignedVarInt(thisIndex - lastIndex, out);
                lastIndex = thisIndex;
                if (laxPrecision) {
                    out.writeFloat((float) element.get());
                } else {
                    out.writeDouble(element.get());
                }
            }
        } else {
            while (iter.hasNext()) {
                Vector.Element element = iter.next();
                if (element.get() == 0) {
                    // TODO(robinanil): Fix the damn iterator for the zero element.
                    continue;
                }
                Varint.writeUnsignedVarInt(element.index(), out);
                if (laxPrecision) {
                    out.writeFloat((float) element.get());
                } else {
                    out.writeDouble(element.get());
                }
            }
        }
    }
    if (named) {
        String name = ((NamedVector) vector).getName();
        out.writeUTF(name == null ? "" : name);
    }
}

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