Package org.apache.commons.numbers.arrays

Class MultidimensionalCounter

  • public final class MultidimensionalCounter
extends java.lang.Object
    Converter between unidimensional storage structure and multidimensional conceptual structure. This utility will convert from indices in a multidimensional structure to the corresponding index in a one-dimensional array. For example, assuming that the ranges (in 3 dimensions) of indices are 2, 4 and 3, the following correspondences, between 3-tuples indices and unidimensional indices, will hold:
    • (0, 0, 0) corresponds to 0
    • (0, 0, 1) corresponds to 1
    • (0, 0, 2) corresponds to 2
    • (0, 1, 0) corresponds to 3
    • ...
    • (1, 0, 0) corresponds to 12
    • ...
    • (1, 3, 2) corresponds to 23

    • Field Summary

      Fields 
      Modifier and Type Field Description
      private int dimension
      Number of dimensions.
      private int last
      Index of last dimension.
      private int[] size
      Counter sizes.
      private int totalSize
      Total number of (one-dimensional) slots.
      private int[] uniCounterOffset
      Offset for each dimension.

    • Constructor Summary

      Constructors 
      Modifier Constructor Description
      private MultidimensionalCounter​(int... size)
      Creates a counter.

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      private static void checkStrictlyPositive​(java.lang.String name, int size)
      Check the size is strictly positive: size > 0.
      private static java.lang.String createIndexOutOfBoundsMessage​(int size, int index)
      Creates the message for the index out of bounds exception.
      int getDimension()
      Gets the number of dimensions of the multidimensional counter.
      int getSize()
      Gets the total number of elements.
      int[] getSizes()
      Gets the number of multidimensional counter slots in each dimension.
      static MultidimensionalCounter of​(int... size)
      Creates a counter.
      int[] toMulti​(int index)
      Converts to a multidimensional counter.
      java.lang.String toString()
      int toUni​(int... c)
      Converts to a unidimensional counter.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

    • Field Detail

      • dimension

        private final int dimension
        Number of dimensions.

      • uniCounterOffset

        private final int[] uniCounterOffset
        Offset for each dimension.

      • size

        private final int[] size
        Counter sizes.

      • totalSize

        private final int totalSize
        Total number of (one-dimensional) slots.

      • last

        private final int last
        Index of last dimension.

    • Constructor Detail

      • MultidimensionalCounter

        private MultidimensionalCounter​(int... size)
        Creates a counter.
        Parameters:
        size - Counter sizes (number of slots in each dimension).
        Throws:
        java.lang.IllegalArgumentException - if one of the sizes is negative or zero.

    • Method Detail

      • of

        public static MultidimensionalCounter of​(int... size)
        Creates a counter.
        Parameters:
        size - Counter sizes (number of slots in each dimension).
        Returns:
        a new instance.
        Throws:
        java.lang.IllegalArgumentException - if one of the sizes is negative or zero.

      • getDimension

        public int getDimension()
        Gets the number of dimensions of the multidimensional counter.
        Returns:
        the number of dimensions.

      • toMulti

        public int[] toMulti​(int index)
        Converts to a multidimensional counter.
        Parameters:
        index - Index in unidimensional counter.
        Returns:
        the multidimensional counts.
        Throws:
        java.lang.IndexOutOfBoundsException - if index is not between 0 and the value returned by getSize() (excluded).

      • toUni

        public int toUni​(int... c)
        Converts to a unidimensional counter.
        Parameters:
        c - Indices in multidimensional counter.
        Returns:
        the index within the unidimensionl counter.
        Throws:
        java.lang.IllegalArgumentException - if the size of c does not match the size of the array given in the constructor.
        java.lang.IndexOutOfBoundsException - if a value of c is not in the range of the corresponding dimension, as defined in the constructor.

      • getSize

        public int getSize()
        Gets the total number of elements.
        Returns:
        the total size of the unidimensional counter.

      • getSizes

        public int[] getSizes()
        Gets the number of multidimensional counter slots in each dimension.
        Returns:
        the number of slots in each dimension.

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object

      • checkStrictlyPositive

        private static void checkStrictlyPositive​(java.lang.String name,
                                          int size)
        Check the size is strictly positive: size > 0.
        Parameters:
        name - the name of the size
        size - the size

      • createIndexOutOfBoundsMessage

        private static java.lang.String createIndexOutOfBoundsMessage​(int size,
                                                              int index)
        Creates the message for the index out of bounds exception.
        Parameters:
        size - the size
        index - the index
        Returns:
        the message