Package jme3utilities.math

Class MyArray

java.lang.Object
jme3utilities.math.MyArray
public final class MyArray extends Object
Utility methods that operate on arrays.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final Logger
    logger
    message logger for this class

  • Method Summary

    Modifier and Type
    Method
    Description
    static com.jme3.bounding.BoundingBox
    aabb(com.jme3.math.Vector3f[] array, com.jme3.bounding.BoundingBox storeResult)
    Determine the smallest axis-aligned bounding box for the vectors in the specified array.
    static int
    countNe(com.jme3.math.Vector3f[] array)
    Count the number of distinct values in the specified array, without distinguishing 0 from -0.
    static int
    countNeSorted(float... array)
    Count distinct the number of distinct values in the specified array, without distinguishing 0 from -0.
    static com.jme3.math.Matrix3f
    covarianceVector3f(float[] input, com.jme3.math.Matrix3f storeResult)
    Determine the sample covariance of the 3-D vectors in the specified float array.
    static boolean
    distinct(float[] vector, int n)
    Test whether the first N elements of the specified vector contain >1 distinct values, without distinguishing 0 from -0.
    static int
    findPreviousIndex(float value, float[] array)
    Find the index of the last value ≤ the specified one in the specified sorted float array, using binary search.
    static int
    first(boolean[] array)
    Find the index of the first true element in the specified boolean array.
    static boolean
    isSorted(float[] array)
    Test whether the specified array is sorted in ascending order with no duplicates.
    static boolean
    isSorted(int[] array)
    Test whether the specified array is sorted in ascending order with no duplicates.
    static boolean
    isSorted(Comparable[] array)
    Test whether the specified array is sorted in ascending order with no duplicates.
    static com.jme3.math.Vector3f
    mean(com.jme3.math.Vector3f[] array, com.jme3.math.Vector3f storeResult)
    Determine the arithmetic mean of a non-empty array of vectors.
    static com.jme3.math.Vector3f
    meanVector3f(float[] input, com.jme3.math.Vector3f storeResult)
    Determine the arithmetic mean of the 3-D vectors in the specified float array.
    static void
    normalize(float[] dataset, float min, float max)
    Normalize a dataset to [0, 1] using the specified min and max.

    Methods inherited from class java.lang.Object

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

  • Field Details

    • logger

      public static final Logger logger
      message logger for this class

  • Method Details

    • aabb

      public static com.jme3.bounding.BoundingBox aabb(com.jme3.math.Vector3f[] array, com.jme3.bounding.BoundingBox storeResult)
      Determine the smallest axis-aligned bounding box for the vectors in the specified array.
      Parameters:
      array - the vectors (not null, not empty, all finite, unaffected)
      storeResult - storage for the result (modified if not null)
      Returns:
      the BoundingBox (either storeResult or a new instance, not null)
      See Also:
      • BoundingBox.containAABB(java.nio.FloatBuffer)

    • covarianceVector3f

      public static com.jme3.math.Matrix3f covarianceVector3f(float[] input, com.jme3.math.Matrix3f storeResult)
      Determine the sample covariance of the 3-D vectors in the specified float array.
      Parameters:
      input - the input array (not null, at least 6 elements, length a multiple of 3, unaffected)
      storeResult - storage for the result (modified if not null)
      Returns:
      the unbiased sample covariance (either storeResult or a new matrix, not null)

    • countNeSorted

      public static int countNeSorted(float... array)
      Count distinct the number of distinct values in the specified array, without distinguishing 0 from -0. The array must be sorted in ascending order.
      Parameters:
      array - the array to analyze (not null, unaffected)
      Returns:
      count (≥0)

    • countNe

      public static int countNe(com.jme3.math.Vector3f[] array)
      Count the number of distinct values in the specified array, without distinguishing 0 from -0.
      Parameters:
      array - the array to analyze (not null, unaffected)
      Returns:
      count (≥0)

    • distinct

      public static boolean distinct(float[] vector, int n)
      Test whether the first N elements of the specified vector contain >1 distinct values, without distinguishing 0 from -0.
      Parameters:
      vector - the array to analyze (not null, unaffected)
      n - number of elements to consider (≥0)
      Returns:
      true if multiple values found, otherwise false

    • findPreviousIndex

      public static int findPreviousIndex(float value, float[] array)
      Find the index of the last value ≤ the specified one in the specified sorted float array, using binary search.
      Parameters:
      value - value to search for
      array - array to search (not null, strictly monotonic increasing order, unaffected)
      Returns:
      array index (≥0) or -1 if array is empty or value≤array[0]
      See Also:

    • first

      public static int first(boolean[] array)
      Find the index of the first true element in the specified boolean array.
      Parameters:
      array - the array to analyze (not null, unaffected)
      Returns:
      the index (≥0, <length) or -1 if no true element found

    • isSorted

      public static boolean isSorted(Comparable[] array)
      Test whether the specified array is sorted in ascending order with no duplicates.
      Parameters:
      array - the array to analyze (not null, unaffected)
      Returns:
      true if sorted, otherwise false

    • isSorted

      public static boolean isSorted(float[] array)
      Test whether the specified array is sorted in ascending order with no duplicates.
      Parameters:
      array - the array to analyze (not null, unaffected)
      Returns:
      true if sorted, otherwise false

    • isSorted

      public static boolean isSorted(int[] array)
      Test whether the specified array is sorted in ascending order with no duplicates.
      Parameters:
      array - the array to analyze (not null, unaffected)
      Returns:
      true if sorted, otherwise false

    • meanVector3f

      public static com.jme3.math.Vector3f meanVector3f(float[] input, com.jme3.math.Vector3f storeResult)
      Determine the arithmetic mean of the 3-D vectors in the specified float array.
      Parameters:
      input - the array to analyze (not null, not empty, length a multiple of 3, unaffected)
      storeResult - storage for the result (modified if not null)
      Returns:
      the mean (either storeResult or a new vector, not null)

    • mean

      public static com.jme3.math.Vector3f mean(com.jme3.math.Vector3f[] array, com.jme3.math.Vector3f storeResult)
      Determine the arithmetic mean of a non-empty array of vectors.
      Parameters:
      array - the vectors to average (not null, not empty, unaffected)
      storeResult - storage for the result (modified if not null)
      Returns:
      the mean (either storeResult or a new vector, not null)

    • normalize

      public static void normalize(float[] dataset, float min, float max)
      Normalize a dataset to [0, 1] using the specified min and max. If min==max, all data will be set to 0.5.
      Parameters:
      dataset - data to normalize (not null, modified)
      min - value to normalize to 0
      max - value to normalize to 1