com.quinncurtis.chart2djava
Class DoubleArray

java.lang.Object
  com.quinncurtis.chart2djava.DoubleArray

Direct Known Subclasses:

TimeArray

public class DoubleArray
extends java.lang.Object

The DoubleArray is an improved version of the standard Array type because it allows automatic and dynamic resizing of the array. The array has a Length property that specifies the number of elements in the array, and a maxCapacity property that specifies the size of the internal Array buffer. The internal buffer can be sized much larger than the Length property, allowing the array to grow in length without forcing a time consuming reallocation and the subsequent copying of all of the data values. Not really important if you are dealing with 10 or 20 element arrays, but very important if you have 1,000,000 element arrays.

Constructor Summary

DoubleArray()
Default constructor.

DoubleArray(double[] x)
Constructor initializes the array using the specified data values.

DoubleArray(double[] x, int maxcap)
Constructor initializes the array using the specified data values.

DoubleArray(int n)
Constructor creates an array of Length n, initialized to zero.

Method Summary

int	add(double r) Adds a new element at the end of the array, increasing the length of the array by one.
int	addRange(double[] x) Adds a array of new values at the end of the array, increasing the length of the array by the length of the source array.
static void	arrayCopy(double[] source, int sourceoffset, double[] dest, int destoffset, int count)
void	clear() Resets (same as clear) the Length property to 0, the maxCapacity property to 16 and reallocates the internal buffer to maxCapacity.
java.lang.Object	clone() Returns an object that is a clone of this array object.
void	copy(DoubleArray source) Copies the source array to the current instance.
static void	copyArray(DoubleArray source, int sourceoffset, DoubleArray dest, int destoffset, int count) Static routine copies all or part of one array to another.
double[]	DataBuffer() Returns a reference to the Array object that represents internal data buffer.
int	delete(int index) Removes an element at the specified index, decreasing the length of the array by one.
double[]	getDataBuffer() Returns a reference to the Array object that represents internal data buffer.
double	getElement(int index) Get the value of a single element in the array.
double[]	getElements() Returns a copy of the data values in the array sized to the number of elements.
int	insert(int index, double r) Inserts an element in the array at the specified index, increasing the length of the array by one.
int	length() This accessor returns the value of the length field which is number of data points in a simple dataset, or the number of x-values in a group dataset.
int	maxCapacity() This accessor returns the value of the maxCapacity field.
void	nDCopy(DoubleArray source) Non-Destructive copy does not reallocate buffers, limits copy to the number of elements in the smaller of two arrays, the source or the current instance.
int	removeAt(int index) Removes an element at the specified index, decreasing the length of the array by one.
void	reset() Resets the Length property to 0, the maxCapacity property to 16 and reallocates the internal buffer to maxCapacity.
int	resize(int newlength) The length of the arrays is set to the specified value.
void	resizeCapacity(int newcapacity) This method reallocates the internal data buffer to the new capacity value.
void	setElement(int index, double r) Set the value of a single element in the array.
int	setElements(double[] source) Initializes the elements of the array, starting at element 0.
int	setElements(double[] source, int count) Initializes the elements of the array, starting at element 0 and continuing for count elements.
int	setElements(DoubleArray source) Initializes the elements of the array, starting at element 0.
int	setElements(DoubleArray source, int count) Initializes the elements of the array, starting at element 0 and continuing for count elements.
int	setLength(int newlength) Resizes the array to the specified length.
void	shiftLeft(int shiftcount, boolean fillzero) Shifts the elements of the array to the left.
int	shiftLeftThenResize(int shiftcount, boolean trim) Shifts the elements of the array to the left.
void	shiftRight(int shiftcount, boolean fillzero) Shifts the elements of the array to the right.
void	TrimToSize() The maxCapacity property is set equal to the Length property of the array and the internal buffer are resized to the new maxCapacity value.

Methods inherited from class java.lang.Object

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

Constructor Detail

DoubleArray

public DoubleArray()

Default constructor.

DoubleArray

public DoubleArray(double[] x)

Constructor initializes the array using the specified data values. The number of elements of the array is set to the Length of the source array, and the internal buffer used to hold the data is set to the same size.

Parameters:

x - The initializing data values.

DoubleArray

public DoubleArray(double[] x,
                   int maxcap)

Constructor initializes the array using the specified data values. The number of elements of the array is set to the Length of the initializing array, while the internal buffer used to hold the data is sized to maxcap.

Parameters:

x - The initializing data values.

maxcap - The internal buffer holding the data values is sized to the value of maxcap. If the number of datavalues exceeds the maxcap limit, the size of maxcap is automatically doubled.

DoubleArray

public DoubleArray(int n)

Constructor creates an array of Length n, initialized to zero.

Parameters:

n - The array is sized to n elements.

Method Detail

add

public int add(double r)

Adds a new element at the end of the array, increasing the length of the array by one. If the maxCapacity property is exceeded the maxCapacity property is automatically doubled and the internal buffer resized accordingly.

Parameters:

r - The new value to add at the end of the array.

Returns:

Returns the new value of the Length property.

addRange

public int addRange(double[] x)

Adds a array of new values at the end of the array, increasing the length of the array by the length of the source array. If the maxCapacity property is exceeded the maxCapacity property is automatically doubled and the internal buffer resized accordingly.

Parameters:

x - An array of new values that are added to the end of the array.

Returns:

Returns the new value of the Length property.

arrayCopy

public static void arrayCopy(double[] source,
                             int sourceoffset,
                             double[] dest,
                             int destoffset,
                             int count)

clear

public void clear()

Resets (same as clear) the Length property to 0, the maxCapacity property to 16 and reallocates the internal buffer to maxCapacity.

clone

public java.lang.Object clone()

Returns an object that is a clone of this array object.

Overrides:

clone in class java.lang.Object

Returns:

Returns a clone of this array object.

copy

public void copy(DoubleArray source)

Copies the source array to the current instance.

Parameters:

source - The source array object.

copyArray

public static void copyArray(DoubleArray source,
                             int sourceoffset,
                             DoubleArray dest,
                             int destoffset,
                             int count)

Static routine copies all or part of one array to another.

Parameters:

source - The source array.

sourceoffset - The index to start copying from in the source array.

dest - The destination array.

destoffset - The index to start copying to in the destination array.

count - The number of array elements to copy.

DataBuffer

public double[] DataBuffer()

Returns a reference to the Array object that represents internal data buffer. This reference will remain valid only as long as the array is not forced to resize, forcing a reallocation of the internal buffer.

delete

public int delete(int index)

Removes an element at the specified index, decreasing the length of the array by one. The size of the internal buffer remains unchanged.

Parameters:

index - The array element that is deleted.

Returns:

Returns the new value of the Length property.

getDataBuffer

public double[] getDataBuffer()

Returns a reference to the Array object that represents internal data buffer. It may be sized to the maxCapacity value, instead of the number of items in the buffer. This reference will remain valid only as long as the array is not forced to resize, forcing a reallocation of the internal buffer.

Returns:

Returns a reference to the Array object that represents the internal data buffer.

getElement

public double getElement(int index)

Get the value of a single element in the array.

Parameters:

index - The array index.

Returns:

Returns the value of the array at the specified index.

getElements

public double[] getElements()

Returns a copy of the data values in the array sized to the number of elements.

Returns:

Returns a copy of the data values in the array sized to the number of elements.

insert

public int insert(int index,
                  double r)

Inserts an element in the array at the specified index, increasing the length of the array by one. If the maxCapacity property is exceeded the maxCapacity property is automatically doubled and the internal buffer resized accordingly.

Parameters:

index - The array element where the new value is inserted.

r - The new value to insert.

Returns:

Returns the new value of the Length property.

length

public int length()

This accessor returns the value of the length field which is number of data points in a simple dataset, or the number of x-values in a group dataset.

maxCapacity

public int maxCapacity()

This accessor returns the value of the maxCapacity field. The maxCapacity property represents the allocated size of the internal Array object used as the data buffer for the array. It is always greater than or equal to the Length property.

nDCopy

public void nDCopy(DoubleArray source)

Non-Destructive copy does not reallocate buffers, limits copy to the number of elements in the smaller of two arrays, the source or the current instance.

Parameters:

source - The source array object.

removeAt

public int removeAt(int index)

Removes an element at the specified index, decreasing the length of the array by one. The size of the internal buffer remains unchanged.

Parameters:

index - The array element that is deleted.

Returns:

Returns the new value of the Length property.

reset

public void reset()

Resets the Length property to 0, the maxCapacity property to 16 and reallocates the internal buffer to maxCapacity.

resize

public int resize(int newlength)

The length of the arrays is set to the specified value. If the new length is greater than the current Length property value, but less or equal to the maxCapacity property value, the Length property is increased to reflect the new value. If the new length is greater than maxCapacity, the maxCapacity value is doubled until it is greater than the new length, and the internal buffer increased accordingly. New, uninitialized array elements are set to zero.

Parameters:

newlength - The array is resized to the new length.

Returns:

Returns the new value of the Length property.

resizeCapacity

public void resizeCapacity(int newcapacity)

This method reallocates the internal data buffer to the new capacity value. The data is preserved. If the new buffer size is less than the number of data values in the old array, the array is truncated. If the new buffer size is greater than the number of data values, the Length property remains the same, but the maxCapacity property is changed and the internal buffer reallocated to the new maxcapcity size. The minimum size for the capacity value is clamped to 8;

Parameters:

newcapacity - The internal buffer holding the data values is sized to the new value of new capacity. The Length property remains unchanged if the new buffer size is larger than the old buffer size, only the buffer size is changed, not the current number of elements in the array.

setElement

public void setElement(int index,
                       double r)

Set the value of a single element in the array.

Parameters:

index - The index to set in the array.

r - The array element at index is set to the value r.*

setElements

public int setElements(double[] source)

Initializes the elements of the array, starting at element 0. The size of the array is set equal to the length of the source array. If the source array is larger than the current length of the array, the array is resized accordingly.

Parameters:

source - An array of new values used to initialize the array. The array will end up the same size as the source array.

Returns:

Returns the new value of the Length property.

setElements

public int setElements(double[] source,
                       int count)

Initializes the elements of the array, starting at element 0 and continuing for count elements. The size of the array is set equal to the length of the source array, or the count, whichever is smaller. If the new length larger than the current length of the array, the array is resized accordingly.

Parameters:

source - An array of new values used to initialize the array. The array will end up the same size as the source array, or the count value, whichever is smaller.

count - Specifies the number of elements to initialize.

Returns:

Returns the new value of the Length property.

setElements

public int setElements(DoubleArray source)

Initializes the elements of the array, starting at element 0. The size of the array is set equal to the length of the source array. If the source array is larger than the current length of the array, the array is resized accordingly.

Parameters:

source - An array of new values used to initialize the array. The array will end up the same size as the source array.

Returns:

Returns the new value of the Length property.

setElements

public int setElements(DoubleArray source,
                       int count)

Initializes the elements of the array, starting at element 0 and continuing for count elements. The size of the array is set equal to the length of the source array, or the count, whichever is smaller. If the new length larger than the current length of the array, the array is resized accordingly.

Parameters:

source - An array of new values used to initialize the array. The array will end up the same size as the source array, or the count value, whichever is smaller.

count - Specifies the number of elements to initialize.

Returns:

Returns the new value of the Length property.

setLength

public int setLength(int newlength)

Resizes the array to the specified length. The maxCapacity property is iteratively doubled until it exceeds the new length, then internal buffer are resized to the new maxCapacity value.

Parameters:

newlength - The array is resized to the new length.

Returns:

Returns the new value of the Length property.

shiftLeft

public void shiftLeft(int shiftcount,
                      boolean fillzero)

Shifts the elements of the array to the left. If you have a 10 element array and shift the array 2 elements to the left, element 7 ends up with the value originally in element 9, element 6 ends up with the value originally in element 8, etc.

Parameters:

shiftcount - The elements are shifted to left by shiftcount elements.

fillzero - Set to true if elements to the right of the final shift point are to be set to zero. In the example above this would apply to elements 8 and 9 in the final, shifted array.

shiftLeftThenResize

public int shiftLeftThenResize(int shiftcount,
                               boolean trim)

Shifts the elements of the array to the left. If you have a 10 element array and shift the array 2 elements to the left, element 7 ends up with the value originally in element 9, element 6 ends up with the value originally in element 8, etc. The array is resized to a size equal to the original array size minus the shift count (Length - shiftcount).

Parameters:

shiftcount - The elements are shifted to left by shiftcount elements.

trim - Set to true if the maxCapacity property is to be set equal to Length property, sizing the internal data buffers to the exact array size.

Returns:

Returns the new value of the Length property.

shiftRight

public void shiftRight(int shiftcount,
                       boolean fillzero)

Shifts the elements of the array to the right. If you have a 10 element array and shift the array 2 elements to the right, element 2 ends up with the value originally in element 0, element 3 ends up with the value originally in element 1, etc.

Parameters:

shiftcount - The elements are shifted to right by shiftcount elements.

fillzero - Set to true if elements to the left of the final shift point are to be set to zero. In the example above this would apply to elements 0 and 1 in the final, shifted array.

TrimToSize

public void TrimToSize()

The maxCapacity property is set equal to the Length property of the array and the internal buffer are resized to the new maxCapacity value. This leaves no "slack" in the internal buffer that allows the array length to grow without forcing a reallocation and copy of all data elements should the length of the array be increased.