Package org.apache.spark.ml.linalg

Class DenseMatrix

Object
org.apache.spark.ml.linalg.DenseMatrix
All Implemented Interfaces:
Serializable, Matrix
public class DenseMatrix extends Object implements Matrix
Column-major dense matrix. The entry values are stored in a single array of doubles with columns listed in sequence. For example, the following matrix 

   1.0 2.0
   3.0 4.0
   5.0 6.0
is stored as [1.0, 3.0, 5.0, 2.0, 4.0, 6.0].

param: numRows number of rows param: numCols number of columns param: values matrix entries in column major if not transposed or in row major otherwise param: isTransposed whether the matrix is transposed. If true, values stores the matrix in row major.

See Also:

  • Constructor Details

    • DenseMatrix

      public DenseMatrix(int numRows, int numCols, double[] values, boolean isTransposed)

    • DenseMatrix

      public DenseMatrix(int numRows, int numCols, double[] values)
      Column-major dense matrix. The entry values are stored in a single array of doubles with columns listed in sequence. For example, the following matrix 
      
   1.0 2.0
   3.0 4.0
   5.0 6.0
      is stored as [1.0, 3.0, 5.0, 2.0, 4.0, 6.0].

      Parameters:
      numRows - number of rows
      numCols - number of columns
      values - matrix entries in column major

  • Method Details

    • zeros

      public static DenseMatrix zeros(int numRows, int numCols)
      Generate a DenseMatrix consisting of zeros.
      Parameters:
      numRows - number of rows of the matrix
      numCols - number of columns of the matrix
      Returns:
      DenseMatrix with size numRows x numCols and values of zeros

    • ones

      public static DenseMatrix ones(int numRows, int numCols)
      Generate a DenseMatrix consisting of ones.
      Parameters:
      numRows - number of rows of the matrix
      numCols - number of columns of the matrix
      Returns:
      DenseMatrix with size numRows x numCols and values of ones

    • eye

      public static DenseMatrix eye(int n)
      Generate an Identity Matrix in DenseMatrix format.
      Parameters:
      n - number of rows and columns of the matrix
      Returns:
      DenseMatrix with size n x n and values of ones on the diagonal

    • rand

      public static DenseMatrix rand(int numRows, int numCols, Random rng)
      Generate a DenseMatrix consisting of i.i.d. uniform random numbers.
      Parameters:
      numRows - number of rows of the matrix
      numCols - number of columns of the matrix
      rng - a random number generator
      Returns:
      DenseMatrix with size numRows x numCols and values in U(0, 1)

    • randn

      public static DenseMatrix randn(int numRows, int numCols, Random rng)
      Generate a DenseMatrix consisting of i.i.d. gaussian random numbers.
      Parameters:
      numRows - number of rows of the matrix
      numCols - number of columns of the matrix
      rng - a random number generator
      Returns:
      DenseMatrix with size numRows x numCols and values in N(0, 1)

    • diag

      public static DenseMatrix diag(Vector vector)
      Generate a diagonal matrix in DenseMatrix format from the supplied values.
      Parameters:
      vector - a Vector that will form the values on the diagonal of the matrix
      Returns:
      Square DenseMatrix with size values.length x values.length and values on the diagonal

    • numRows

      public int numRows()
      Description copied from interface: Matrix
      Number of rows.
      Specified by:
      numRows in interface Matrix

    • numCols

      public int numCols()
      Description copied from interface: Matrix
      Number of columns.
      Specified by:
      numCols in interface Matrix

    • values

      public double[] values()

    • isTransposed

      public boolean isTransposed()
      Description copied from interface: Matrix
      Flag that keeps track whether the matrix is transposed or not. False by default.
      Specified by:
      isTransposed in interface Matrix

    • equals

      public boolean equals(Object o)
      Overrides:
      equals in class Object

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • apply

      public double apply(int i, int j)
      Description copied from interface: Matrix
      Gets the (i, j)-th element.
      Specified by:
      apply in interface Matrix

    • copy

      public DenseMatrix copy()
      Description copied from interface: Matrix
      Get a deep copy of the matrix.
      Specified by:
      copy in interface Matrix

    • transpose

      public DenseMatrix transpose()
      Description copied from interface: Matrix
      Transpose the Matrix. Returns a new Matrix instance sharing the same underlying data.
      Specified by:
      transpose in interface Matrix
      Returns:
      (undocumented)

    • foreachActive

      public void foreachActive(scala.Function3<Object,Object,Object,scala.runtime.BoxedUnit> f)
      Description copied from interface: Matrix
      Applies a function f to all the active elements of dense and sparse matrix. The ordering of the elements are not defined.

      Specified by:
      foreachActive in interface Matrix
      Parameters:
      f - the function takes three parameters where the first two parameters are the row and column indices respectively with the type Int, and the final parameter is the corresponding value in the matrix with type Double.

    • numNonzeros

      public int numNonzeros()
      Description copied from interface: Matrix
      Find the number of non-zero active values.
      Specified by:
      numNonzeros in interface Matrix
      Returns:
      (undocumented)

    • numActives

      public int numActives()
      Description copied from interface: Matrix
      Find the number of values stored explicitly. These values can be zero as well.
      Specified by:
      numActives in interface Matrix
      Returns:
      (undocumented)

    • colIter

      public scala.collection.Iterator<Vector> colIter()
      Description copied from interface: Matrix
      Returns an iterator of column vectors. This operation could be expensive, depending on the underlying storage.
      Specified by:
      colIter in interface Matrix
      Returns:
      (undocumented)