public class SparseDoubleMatrix1Dextends DoubleMatrix1DSparse hashed 1-d matrix (aka vector) holding double elements.First see the package summary and javadoc tree view to get the broad picture.
Note that this implementation is not synchronized.Uses a
OpenIntDoubleHashMap, which is a compact and performant hashing technique.
- are never set to non-zero values do not use any memory.
- switch from zero to non-zero state do use memory.
- switch back from non-zero to zero state also do use memory. However, their memory is automatically reclaimed from time to time. It can also manually be reclaimed by calling
worst case: memory [bytes] = (1/minLoadFactor) * nonZeros * 13.
best case: memory [bytes] = (1/maxLoadFactor) * nonZeros * 13.
Where nonZeros = cardinality() is the number of non-zero cells.Thus, a 1000000 matrix with minLoadFactor=0.25 and maxLoadFactor=0.5 and 1000000 non-zero cells consumes between 25 MB and 50 MB.The same 1000000 matrix with 1000 non-zero cells consumes between 25 and 50 KB.
This class offers expected time complexity O(1) (i.e. constant time) for the basic operationsget, getQuick, set, setQuick and sizeassuming the hash function disperses the elements properly among the buckets.Otherwise, pathological cases, although highly improbable, can occur, degrading performance to O(N) in the worst case.As such this sparse class is expected to have no worse time complexity than its dense counterpart
DenseDoubleMatrix1D.However, constant factors are considerably larger.
- See Also:
- Serialized Form