Package org.apache.commons.math.linear

Class MatrixUtils

  • public class MatrixUtils
extends java.lang.Object
    A collection of static methods that operate on or return matrices.

    • Method Detail

      • createRealMatrix

        public static RealMatrix createRealMatrix​(int rows,
                                          int columns)
        Returns a RealMatrix with specified dimensions.

        The type of matrix returned depends on the dimension. Below 212 elements (i.e. 4096 elements or 64×64 for a square matrix) which can be stored in a 32kB array, a Array2DRowRealMatrix instance is built. Above this threshold a BlockRealMatrix instance is built.

        The matrix elements are all set to 0.0.

        Parameters:
        rows - number of rows of the matrix
        columns - number of columns of the matrix
        Returns:
        RealMatrix with specified dimensions
        See Also:
        createRealMatrix(double[][])

      • createFieldMatrix

        public static <T extends FieldElement<T>> FieldMatrix<T> createFieldMatrix​(Field<T> field,
                                                                           int rows,
                                                                           int columns)
        Returns a FieldMatrix with specified dimensions.

        The type of matrix returned depends on the dimension. Below 212 elements (i.e. 4096 elements or 64×64 for a square matrix), a FieldMatrix instance is built. Above this threshold a BlockFieldMatrix instance is built.

        The matrix elements are all set to field.getZero().

        Type Parameters:
        T - the type of the field elements
        Parameters:
        field - field to which the matrix elements belong
        rows - number of rows of the matrix
        columns - number of columns of the matrix
        Returns:
        FieldMatrix with specified dimensions
        Since:
        2.0
        See Also:
        createFieldMatrix(FieldElement[][])

      • createRealMatrix

        public static RealMatrix createRealMatrix​(double[][] data)
        Returns a RealMatrix whose entries are the the values in the the input array.

        The type of matrix returned depends on the dimension. Below 212 elements (i.e. 4096 elements or 64×64 for a square matrix) which can be stored in a 32kB array, a Array2DRowRealMatrix instance is built. Above this threshold a BlockRealMatrix instance is built.

        The input array is copied, not referenced.

        Parameters:
        data - input array
        Returns:
        RealMatrix containing the values of the array
        Throws:
        java.lang.IllegalArgumentException - if data is not rectangular (not all rows have the same length) or empty
        java.lang.NullPointerException - if either data or data[0] is null
        See Also:
        createRealMatrix(int, int)

      • createFieldMatrix

        public static <T extends FieldElement<T>> FieldMatrix<T> createFieldMatrix​(T[][] data)
        Returns a FieldMatrix whose entries are the the values in the the input array.

        The type of matrix returned depends on the dimension. Below 212 elements (i.e. 4096 elements or 64×64 for a square matrix), a FieldMatrix instance is built. Above this threshold a BlockFieldMatrix instance is built.

        The input array is copied, not referenced.

        Type Parameters:
        T - the type of the field elements
        Parameters:
        data - input array
        Returns:
        RealMatrix containing the values of the array
        Throws:
        java.lang.IllegalArgumentException - if data is not rectangular (not all rows have the same length) or empty
        java.lang.NullPointerException - if either data or data[0] is null
        Since:
        2.0
        See Also:
        createFieldMatrix(Field, int, int)

      • createRealIdentityMatrix

        public static RealMatrix createRealIdentityMatrix​(int dimension)
        Returns dimension x dimension identity matrix.
        Parameters:
        dimension - dimension of identity matrix to generate
        Returns:
        identity matrix
        Throws:
        java.lang.IllegalArgumentException - if dimension is not positive
        Since:
        1.1

      • createFieldIdentityMatrix

        public static <T extends FieldElement<T>> FieldMatrix<T> createFieldIdentityMatrix​(Field<T> field,
                                                                                   int dimension)
        Returns dimension x dimension identity matrix.
        Type Parameters:
        T - the type of the field elements
        Parameters:
        field - field to which the elements belong
        dimension - dimension of identity matrix to generate
        Returns:
        identity matrix
        Throws:
        java.lang.IllegalArgumentException - if dimension is not positive
        Since:
        2.0

      • createBigIdentityMatrix

        @Deprecated
public static BigMatrix createBigIdentityMatrix​(int dimension)
        Deprecated.
        since 2.0, replaced by createFieldIdentityMatrix(Field, int)
        Returns dimension x dimension identity matrix.
        Parameters:
        dimension - dimension of identity matrix to generate
        Returns:
        identity matrix
        Throws:
        java.lang.IllegalArgumentException - if dimension is not positive
        Since:
        1.1

      • createRealDiagonalMatrix

        public static RealMatrix createRealDiagonalMatrix​(double[] diagonal)
        Returns a diagonal matrix with specified elements.
        Parameters:
        diagonal - diagonal elements of the matrix (the array elements will be copied)
        Returns:
        diagonal matrix
        Since:
        2.0

      • createFieldDiagonalMatrix

        public static <T extends FieldElement<T>> FieldMatrix<T> createFieldDiagonalMatrix​(T[] diagonal)
        Returns a diagonal matrix with specified elements.
        Type Parameters:
        T - the type of the field elements
        Parameters:
        diagonal - diagonal elements of the matrix (the array elements will be copied)
        Returns:
        diagonal matrix
        Since:
        2.0

      • createBigMatrix

        @Deprecated
public static BigMatrix createBigMatrix​(double[][] data)
        Deprecated.
        since 2.0 replaced by createFieldMatrix(FieldElement[][])
        Returns a BigMatrix whose entries are the the values in the the input array. The input array is copied, not referenced.
        Parameters:
        data - input array
        Returns:
        RealMatrix containing the values of the array
        Throws:
        java.lang.IllegalArgumentException - if data is not rectangular (not all rows have the same length) or empty
        java.lang.NullPointerException - if data is null

      • createBigMatrix

        @Deprecated
public static BigMatrix createBigMatrix​(java.math.BigDecimal[][] data)
        Deprecated.
        since 2.0 replaced by createFieldMatrix(FieldElement[][])
        Returns a BigMatrix whose entries are the the values in the the input array. The input array is copied, not referenced.
        Parameters:
        data - input array
        Returns:
        RealMatrix containing the values of the array
        Throws:
        java.lang.IllegalArgumentException - if data is not rectangular (not all rows have the same length) or empty
        java.lang.NullPointerException - if data is null

      • createBigMatrix

        @Deprecated
public static BigMatrix createBigMatrix​(java.math.BigDecimal[][] data,
                                        boolean copyArray)
        Deprecated.
        since 2.0 replaced by createFieldMatrix(FieldElement[][])
        Returns a BigMatrix whose entries are the the values in the the input array.

        If an array is built specially in order to be embedded in a BigMatrix and not used directly, the copyArray may be set to false

        Parameters:
        data - data for new matrix
        copyArray - if true, the input array will be copied, otherwise it will be referenced
        Returns:
        BigMatrix containing the values of the array
        Throws:
        java.lang.IllegalArgumentException - if data is not rectangular (not all rows have the same length) or empty
        java.lang.NullPointerException - if data is null
        See Also:
        createRealMatrix(double[][])

      • createBigMatrix

        @Deprecated
public static BigMatrix createBigMatrix​(java.lang.String[][] data)
        Deprecated.
        since 2.0 replaced by createFieldMatrix(FieldElement[][])
        Returns a BigMatrix whose entries are the the values in the the input array. The input array is copied, not referenced.
        Parameters:
        data - input array
        Returns:
        RealMatrix containing the values of the array
        Throws:
        java.lang.IllegalArgumentException - if data is not rectangular (not all rows have the same length) or empty
        java.lang.NullPointerException - if data is null

      • createRealVector

        public static RealVector createRealVector​(double[] data)
        Creates a RealVector using the data from the input array.
        Parameters:
        data - the input data
        Returns:
        a data.length RealVector
        Throws:
        java.lang.IllegalArgumentException - if data is empty
        java.lang.NullPointerException - if datais null

      • createFieldVector

        public static <T extends FieldElement<T>> FieldVector<T> createFieldVector​(T[] data)
        Creates a FieldVector using the data from the input array.
        Type Parameters:
        T - the type of the field elements
        Parameters:
        data - the input data
        Returns:
        a data.length FieldVector
        Throws:
        java.lang.IllegalArgumentException - if data is empty
        java.lang.NullPointerException - if datais null

      • createRowRealMatrix

        public static RealMatrix createRowRealMatrix​(double[] rowData)
        Creates a row RealMatrix using the data from the input array.
        Parameters:
        rowData - the input row data
        Returns:
        a 1 x rowData.length RealMatrix
        Throws:
        java.lang.IllegalArgumentException - if rowData is empty
        java.lang.NullPointerException - if rowDatais null

      • createRowFieldMatrix

        public static <T extends FieldElement<T>> FieldMatrix<T> createRowFieldMatrix​(T[] rowData)
        Creates a row FieldMatrix using the data from the input array.
        Type Parameters:
        T - the type of the field elements
        Parameters:
        rowData - the input row data
        Returns:
        a 1 x rowData.length FieldMatrix
        Throws:
        java.lang.IllegalArgumentException - if rowData is empty
        java.lang.NullPointerException - if rowDatais null

      • createRowBigMatrix

        @Deprecated
public static BigMatrix createRowBigMatrix​(double[] rowData)
        Deprecated.
        since 2.0 replaced by createRowFieldMatrix(FieldElement[])
        Creates a row BigMatrix using the data from the input array.
        Parameters:
        rowData - the input row data
        Returns:
        a 1 x rowData.length BigMatrix
        Throws:
        java.lang.IllegalArgumentException - if rowData is empty
        java.lang.NullPointerException - if rowDatais null

      • createRowBigMatrix

        @Deprecated
public static BigMatrix createRowBigMatrix​(java.math.BigDecimal[] rowData)
        Deprecated.
        since 2.0 replaced by createRowFieldMatrix(FieldElement[])
        Creates a row BigMatrix using the data from the input array.
        Parameters:
        rowData - the input row data
        Returns:
        a 1 x rowData.length BigMatrix
        Throws:
        java.lang.IllegalArgumentException - if rowData is empty
        java.lang.NullPointerException - if rowDatais null

      • createRowBigMatrix

        @Deprecated
public static BigMatrix createRowBigMatrix​(java.lang.String[] rowData)
        Deprecated.
        since 2.0 replaced by createRowFieldMatrix(FieldElement[])
        Creates a row BigMatrix using the data from the input array.
        Parameters:
        rowData - the input row data
        Returns:
        a 1 x rowData.length BigMatrix
        Throws:
        java.lang.IllegalArgumentException - if rowData is empty
        java.lang.NullPointerException - if rowDatais null

      • createColumnRealMatrix

        public static RealMatrix createColumnRealMatrix​(double[] columnData)
        Creates a column RealMatrix using the data from the input array.
        Parameters:
        columnData - the input column data
        Returns:
        a columnData x 1 RealMatrix
        Throws:
        java.lang.IllegalArgumentException - if columnData is empty
        java.lang.NullPointerException - if columnDatais null

      • createColumnFieldMatrix

        public static <T extends FieldElement<T>> FieldMatrix<T> createColumnFieldMatrix​(T[] columnData)
        Creates a column FieldMatrix using the data from the input array.
        Type Parameters:
        T - the type of the field elements
        Parameters:
        columnData - the input column data
        Returns:
        a columnData x 1 FieldMatrix
        Throws:
        java.lang.IllegalArgumentException - if columnData is empty
        java.lang.NullPointerException - if columnDatais null

      • createColumnBigMatrix

        @Deprecated
public static BigMatrix createColumnBigMatrix​(double[] columnData)
        Deprecated.
        since 2.0 replaced by createColumnFieldMatrix(FieldElement[])
        Creates a column BigMatrix using the data from the input array.
        Parameters:
        columnData - the input column data
        Returns:
        a columnData x 1 BigMatrix
        Throws:
        java.lang.IllegalArgumentException - if columnData is empty
        java.lang.NullPointerException - if columnDatais null

      • createColumnBigMatrix

        @Deprecated
public static BigMatrix createColumnBigMatrix​(java.math.BigDecimal[] columnData)
        Deprecated.
        since 2.0 replaced by createColumnFieldMatrix(FieldElement[])
        Creates a column BigMatrix using the data from the input array.
        Parameters:
        columnData - the input column data
        Returns:
        a columnData x 1 BigMatrix
        Throws:
        java.lang.IllegalArgumentException - if columnData is empty
        java.lang.NullPointerException - if columnDatais null

      • createColumnBigMatrix

        @Deprecated
public static BigMatrix createColumnBigMatrix​(java.lang.String[] columnData)
        Deprecated.
        since 2.0 replaced by createColumnFieldMatrix(FieldElement[])
        Creates a column BigMatrix using the data from the input array.
        Parameters:
        columnData - the input column data
        Returns:
        a columnData x 1 BigMatrix
        Throws:
        java.lang.IllegalArgumentException - if columnData is empty
        java.lang.NullPointerException - if columnDatais null

      • checkRowIndex

        public static void checkRowIndex​(AnyMatrix m,
                                 int row)
        Check if a row index is valid.
        Parameters:
        m - matrix containing the submatrix
        row - row index to check
        Throws:
        MatrixIndexException - if index is not valid

      • checkColumnIndex

        public static void checkColumnIndex​(AnyMatrix m,
                                    int column)
                             throws MatrixIndexException
        Check if a column index is valid.
        Parameters:
        m - matrix containing the submatrix
        column - column index to check
        Throws:
        MatrixIndexException - if index is not valid

      • checkSubMatrixIndex

        public static void checkSubMatrixIndex​(AnyMatrix m,
                                       int startRow,
                                       int endRow,
                                       int startColumn,
                                       int endColumn)
        Check if submatrix ranges indices are valid. Rows and columns are indicated counting from 0 to n-1.
        Parameters:
        m - matrix containing the submatrix
        startRow - Initial row index
        endRow - Final row index
        startColumn - Initial column index
        endColumn - Final column index
        Throws:
        MatrixIndexException - if the indices are not valid

      • checkSubMatrixIndex

        public static void checkSubMatrixIndex​(AnyMatrix m,
                                       int[] selectedRows,
                                       int[] selectedColumns)
                                throws MatrixIndexException
        Check if submatrix ranges indices are valid. Rows and columns are indicated counting from 0 to n-1.
        Parameters:
        m - matrix containing the submatrix
        selectedRows - Array of row indices.
        selectedColumns - Array of column indices.
        Throws:
        MatrixIndexException - if row or column selections are not valid

      • checkAdditionCompatible

        public static void checkAdditionCompatible​(AnyMatrix left,
                                           AnyMatrix right)
                                    throws java.lang.IllegalArgumentException
        Check if matrices are addition compatible
        Parameters:
        left - left hand side matrix
        right - right hand side matrix
        Throws:
        java.lang.IllegalArgumentException - if matrices are not addition compatible

      • checkSubtractionCompatible

        public static void checkSubtractionCompatible​(AnyMatrix left,
                                              AnyMatrix right)
                                       throws java.lang.IllegalArgumentException
        Check if matrices are subtraction compatible
        Parameters:
        left - left hand side matrix
        right - right hand side matrix
        Throws:
        java.lang.IllegalArgumentException - if matrices are not subtraction compatible

      • checkMultiplicationCompatible

        public static void checkMultiplicationCompatible​(AnyMatrix left,
                                                 AnyMatrix right)
                                          throws java.lang.IllegalArgumentException
        Check if matrices are multiplication compatible
        Parameters:
        left - left hand side matrix
        right - right hand side matrix
        Throws:
        java.lang.IllegalArgumentException - if matrices are not multiplication compatible

      • serializeRealVector

        public static void serializeRealVector​(RealVector vector,
                                       java.io.ObjectOutputStream oos)
                                throws java.io.IOException
        Serialize a RealVector.

        This method is intended to be called from within a private writeObject method (after a call to oos.defaultWriteObject()) in a class that has a RealVector field, which should be declared transient. This way, the default handling does not serialize the vector (the RealVector interface is not serializable by default) but this method does serialize it specifically.

        The following example shows how a simple class with a name and a real vector should be written: 

        
 public class NamedVector implements Serializable {

     private final String name;
     private final transient RealVector coefficients;

     // omitted constructors, getters ...

     private void writeObject(ObjectOutputStream oos) throws IOException {
         oos.defaultWriteObject();  // takes care of name field
         MatrixUtils.serializeRealVector(coefficients, oos);
     }

     private void readObject(ObjectInputStream ois) throws ClassNotFoundException, IOException {
         ois.defaultReadObject();  // takes care of name field
         MatrixUtils.deserializeRealVector(this, "coefficients", ois);
     }

 }

        Parameters:
        vector - real vector to serialize
        oos - stream where the real vector should be written
        Throws:
        java.io.IOException - if object cannot be written to stream
        See Also:
        deserializeRealVector(Object, String, ObjectInputStream)

      • deserializeRealVector

        public static void deserializeRealVector​(java.lang.Object instance,
                                         java.lang.String fieldName,
                                         java.io.ObjectInputStream ois)
                                  throws java.lang.ClassNotFoundException,
                                         java.io.IOException
        Deserialize a RealVector field in a class.

        This method is intended to be called from within a private readObject method (after a call to ois.defaultReadObject()) in a class that has a RealVector field, which should be declared transient. This way, the default handling does not deserialize the vector (the RealVector interface is not serializable by default) but this method does deserialize it specifically.

        Parameters:
        instance - instance in which the field must be set up
        fieldName - name of the field within the class (may be private and final)
        ois - stream from which the real vector should be read
        Throws:
        java.lang.ClassNotFoundException - if a class in the stream cannot be found
        java.io.IOException - if object cannot be read from the stream
        See Also:
        serializeRealVector(RealVector, ObjectOutputStream)

      • serializeRealMatrix

        public static void serializeRealMatrix​(RealMatrix matrix,
                                       java.io.ObjectOutputStream oos)
                                throws java.io.IOException
        Serialize a RealMatrix.

        This method is intended to be called from within a private writeObject method (after a call to oos.defaultWriteObject()) in a class that has a RealMatrix field, which should be declared transient. This way, the default handling does not serialize the matrix (the RealMatrix interface is not serializable by default) but this method does serialize it specifically.

        The following example shows how a simple class with a name and a real matrix should be written: 

        
 public class NamedMatrix implements Serializable {

     private final String name;
     private final transient RealMatrix coefficients;

     // omitted constructors, getters ...

     private void writeObject(ObjectOutputStream oos) throws IOException {
         oos.defaultWriteObject();  // takes care of name field
         MatrixUtils.serializeRealMatrix(coefficients, oos);
     }

     private void readObject(ObjectInputStream ois) throws ClassNotFoundException, IOException {
         ois.defaultReadObject();  // takes care of name field
         MatrixUtils.deserializeRealMatrix(this, "coefficients", ois);
     }

 }

        Parameters:
        matrix - real matrix to serialize
        oos - stream where the real matrix should be written
        Throws:
        java.io.IOException - if object cannot be written to stream
        See Also:
        deserializeRealMatrix(Object, String, ObjectInputStream)

      • deserializeRealMatrix

        public static void deserializeRealMatrix​(java.lang.Object instance,
                                         java.lang.String fieldName,
                                         java.io.ObjectInputStream ois)
                                  throws java.lang.ClassNotFoundException,
                                         java.io.IOException
        Deserialize a RealMatrix field in a class.

        This method is intended to be called from within a private readObject method (after a call to ois.defaultReadObject()) in a class that has a RealMatrix field, which should be declared transient. This way, the default handling does not deserialize the matrix (the RealMatrix interface is not serializable by default) but this method does deserialize it specifically.

        Parameters:
        instance - instance in which the field must be set up
        fieldName - name of the field within the class (may be private and final)
        ois - stream from which the real matrix should be read
        Throws:
        java.lang.ClassNotFoundException - if a class in the stream cannot be found
        java.io.IOException - if object cannot be read from the stream
        See Also:
        serializeRealMatrix(RealMatrix, ObjectOutputStream)