Examples of edu.ucla.sspace.util.SparseIntArray

edu.ucla.sspace.util.SparseIntArray

A sparse {@code int} array. This class trades increased space efficiency atthe cost of decreased performance.

This class also provides additional primitive accessor methods. This allows users to invoke {@code get} and {@code set} without marshalling primitivetypes to their {@link Integer} equivalents unnecessarily.

The {@code get} operation runs in logarithmic time. The {@code set}operation runs in consant time if setting an existing non-zero value to a non-zero value. However, if the {@code set} invocation sets a zero value tonon-zero, the operation is linear with the size of the array.

Instance offer a space savings of retaining only the non-zero indices and values. For large array with only a few values set, this offers a huge savings. However, as the cardinality of the array grows in relation to its size, a dense {@code int[]} array will offer better performance in both spaceand time. This is especially true if the sparse array instance approaches a cardinality to size ratio of {@code .5}.

This class supports iterating over the non-zero indices and values in the array via the {@link #iterator()} method. The indices will be returned insorted order. In cases where both the values and indices are needed, iteration will be faster, {@code O(k)}, than using {@link #getElementIndices()} and {@link #getPrimitive(int)} together, {@code O(k log(k))}, where {@code k} is the number of non-zero indices. The iteratorreturned by this class is not thread-safe and will not throw an exception if the array is concurrently modified during iteration. @see SparseArray

     * Creates a new vector of the specified length
     *
     * @param length the length of this vector
     */
    public CompactSparseIntegerVector(int length) {
        intArray = new SparseIntArray(length);
        magnitude = 0;
    }

     * to either will not be reflected in the other.
     *
     * @param v the intial values for this vector to have
     */
    public CompactSparseIntegerVector(IntegerVector v) {
        intArray = new SparseIntArray(v.length());
        if (v instanceof SparseVector) {
            SparseVector sv = (SparseVector)v;
            for (int i : sv.getNonZeroIndices())
                intArray.set(i, v.get(i));
        }

     * changes to either will not be reflected in the other.
     *
     * @param values the intial values for this vector to have
     */
    public CompactSparseIntegerVector(int[] values) {
        intArray = new SparseIntArray(values);
        magnitude = -1;
    }

Examples of edu.ucla.sspace.util.SparseIntArray

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