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Class pmr.euclid.RealArray

java.lang.Object
   |
   +----pmr.euclid.Status
           |
           +----pmr.euclid.RealArray

public class RealArray

extends Status

RealArray - array of doubles

RealArray represents a 1-dimensional vector/array of doubles and is basically a wrapper for double[] in Java There are a lot of useful member functions (sorting, ranges, parallel operations, etc. - have a look)

The default is an array with zero points. All arrays are valid objects.

Attempting to create an array with < 0 points creates a default array (zero points).

Since double[] knows its length (unlike C), there are many cases where double[] can be safely used. However it is not a first-class object and RealArray supplies this feature. double[] is referenceable through getArray().

Author:

(C) P. Murray-Rust, 1996

RealArray()

default is an array of zero points

RealArray(double[])

from an existing double[] (which knows its length)

RealArray(int)

creates n-element array initialised to 0.0

RealArray(int, double)

set all elements of the array to a given value

RealArray(int, double, double)

This gives a nelem-element array initialised to elem1+(i-1)*delta

RealArray(int, double[])

Formed by feeding in an existing array; requires the size.

RealArray(int, String, double)

Create a given 'shape' of array for data filtering.

RealArray(IntArray)

convert an IntArray to a RealArray

RealArray(RealArray)

copy constructor

RealArray(RealArray, int, int)

subarray of another array - inclusive; if low > high or other silly indices, creates default array

RealArray(String)

from a String with space-separated strings representing Reals

RealArray(String[])

from an array of Strings (which must represent Reals)

absSumAllElements()

absolute sum of all elements

addArray(RealArray)

append elements

addElement(double)

append element

applyFilter(RealArray)

apply filter (i.e.

clearArray()

clear all elements of array

clone()

clones another RealArray

copy(double[])

copy a double[] into a new one

cumulativeSum()

cumulative sum of array (new RA contains
elem[i] = sum(k = 0 to i) f[k]

does not modify 'this'

deleteElement(int)

delete element and close up; if outside range, take no action

deleteElements(double[], int, int)

delete elements (lo - > hi inclusive) in a float[] and close up; if hi >= float.length hi is reset to float.length-1.

deleteElements(int, int)

delete elements and close up; if outside range take no action

dotProduct(RealArray)

dot product of two RealArrays - if of same length - else zero

elementAt(int)

extracts a given element from the array

equals(RealArray)

are two arrays equal in all elements?

equals(RealArray, double)

are two arrays equal in all elements? (use epsilon as tolerance)

euclideanLength()

Euclidean length of vector

getArray()

return the array as a double[]; this has to resize the array to the precise length used , or confusion will result! Note that this gives the user access to the actual array, so that they can alter its contents.

getReorderedArray(IntSet)

reorder by index in IntSet; does NOT modify array

getReverseArray()

return the elements in reverse order as double[]

getStringValues()

returns values as strings

getSubArray(int, int)

RHS: get a subRealArray from element start to end

indexOfLargestElement()

index of largest element; returns -1 if zero element array

indexOfSmallestElement()

index of smallest element

indexSortAscending()

indexSortDescending()

sort array into descending order via indexes; array NOT MODIFIED

innerProduct()

inner product - same as dotProduct

inRange(RealRange)

return index of elements within a given range

insertArray(int, RealArray)

insert a RealArray at position elem and expand

insertElementAt(int, double)

insert element and expand; if outside range, take no action

isClear()

is the array filled with zeros?

largestElement()

value of largest element

main(String[])

multiplyBy(double)

array multiplication by a scalar; does NOT modify 'this'

negative()

change the sign of all elements; MODIFIES this

outOfRange(RealRange)

return index of elements outside a given range

plus(RealArray)

array addition - adds conformable arrays

range()

range of array (default RealRange for zero array)

reverse()

MODIFIES array to be in reverse order

rms()

root mean square sqrt(sigma(x(i)**2)/n)

setAllElements(double)

initialise array to given double[]

setElementAt(int, double)

set a given element into the array; must be less than current max index

setElements(int, double[])

copy a smaller array into the array statrting at start

setMaxIndex(int)

reset the maximum index (for when poking elements) (no other effect)

shallowCopy(RealArray)

shallowCopy

size()

get actual number of elements

smallestElement()

value of smallest element

sortAscending()

MODIFIES array to be in ascending order

sortDescending()

MODIFIES array to be in ascending order

subtract(RealArray)

array subtraction - subtracts conformable arrays

sumAllElements()

sum all elements

test()

toString()

concatenates values with spaces

unitVector()

get unit vector

  public RealArray()

default is an array of zero points

  public RealArray(int n)

creates n-element array initialised to 0.0

  public RealArray(int n,
                   double elem1,
                   double delta)

This gives a nelem-element array initialised to elem1+(i-1)*delta

  public RealArray(int n,
                   double elem1)

set all elements of the array to a given value

  public RealArray(int n,
                   double arr[])

Formed by feeding in an existing array; requires the size. (You can use the *.length of the array if necessary)

  public RealArray(double arr[])

from an existing double[] (which knows its length)

  public RealArray(IntArray ia)

convert an IntArray to a RealArray

  public RealArray(RealArray m,
                   int low,
                   int high)

subarray of another array - inclusive; if low > high or other silly indices, creates default array

  public RealArray(RealArray m)

copy constructor

  public RealArray(int nn,
                   String shape,
                   double maxval)

Create a given 'shape' of array for data filtering. An intended use is with RealArray.arrayFilter(). The shapes (before scaling by maxval) are:

• "TRIANGLE"; 1/nn, 2/nn, ... 1 ... 2/nn, 1/nn; nelem is set to 2*nn - 1
• "ZIGZAG"; 1/nn, 2/nn, ... 1 ... 1/nn, 0, -1/nn, -2/nn, -1, ... -1/nn,; nelem is set to 4*nn - 1

  public RealArray(String strings[]) throws NumberFormatException

from an array of Strings (which must represent Reals)

Throws: NumberFormatException

a string could not be interpreted as Real

  public RealArray(String string) throws NumberFormatException

from a String with space-separated strings representing Reals

Throws: NumberFormatException

a string could not be interpreted as Real

  public Object clone()

clones another RealArray

Overrides:

clone in class Object

  public void shallowCopy(RealArray m)

shallowCopy

  public double elementAt(int elem) throws ArrayIndexOutOfBoundsException

extracts a given element from the array

Throws: ArrayIndexOutOfBoundsException

elem >= size of this

  public int size()

get actual number of elements

  public double[] getArray()

return the array as a double[]; this has to resize the array to the precise length used , or confusion will result! Note that this gives the user access to the actual array, so that they can alter its contents. This should be used with care, but Java should stop any access outside the buffer limits.

  public void clearArray()

clear all elements of array

  public double[] getReverseArray()

return the elements in reverse order as double[]

  public void setMaxIndex(int max)

reset the maximum index (for when poking elements) (no other effect)

  public boolean equals(RealArray f) throws UnequalLengthArraysException

are two arrays equal in all elements?

Throws: UnequalLengthArraysException

f is different size from this

  public boolean equals(RealArray f,
                        double epsilon) throws UnequalLengthArraysException

are two arrays equal in all elements? (use epsilon as tolerance)

Throws: UnequalLengthArraysException

f is different size from this

  public RealArray plus(RealArray f) throws UnequalLengthArraysException

array addition - adds conformable arrays

Throws: UnequalLengthArraysException

f is different size from this

  public RealArray subtract(RealArray f) throws UnequalLengthArraysException

array subtraction - subtracts conformable arrays

Throws: UnequalLengthArraysException

f is different size from this

  public void negative()

change the sign of all elements; MODIFIES this

  public RealArray multiplyBy(double f)

array multiplication by a scalar; does NOT modify 'this'

  public void setElementAt(int elem,
                           double f) throws ArrayIndexOutOfBoundsException

set a given element into the array; must be less than current max index

Throws: ArrayIndexOutOfBoundsException

elem >= size of this

  public RealArray getSubArray(int start,
                               int end)

RHS: get a subRealArray from element start to end

  public void setElements(int start,
                          double a[])

copy a smaller array into the array statrting at start

  public boolean isClear()

is the array filled with zeros?

  public void setAllElements(double f)

initialise array to given double[]

  public double sumAllElements()

sum all elements

  public double absSumAllElements()

absolute sum of all elements

  public double innerProduct()

inner product - same as dotProduct

  public double dotProduct(RealArray f) throws UnequalLengthArraysException

dot product of two RealArrays - if of same length - else zero

Throws: UnequalLengthArraysException

f is different size from this

  public double euclideanLength()

Euclidean length of vector

  public double rms() throws ArrayTooSmallException

root mean square sqrt(sigma(x(i)**2)/n)

Throws: ArrayTooSmallException

must have at least 1 point

  public RealArray unitVector() throws ZeroLengthVectorException

get unit vector

Throws: ZeroLengthVectorException

elements of this are all zero

  public RealArray cumulativeSum()

cumulative sum of array (new RA contains
elem[i] = sum(k = 0 to i) f[k]

does not modify 'this'

  public RealArray applyFilter(RealArray filter)

apply filter (i.e. convolute RA with another RA). This is 1-D image processing. If filter has <= 1 element, return this unchanged. filter should have an odd number of elements.

The filter can be created with a RealArray constructor

  public int indexOfLargestElement()

index of largest element; returns -1 if zero element array

  public int indexOfSmallestElement()

index of smallest element

  public double largestElement()

value of largest element

  public double smallestElement()

value of smallest element

  public RealRange range()

range of array (default RealRange for zero array)

  public void deleteElement(int elem)

delete element and close up; if outside range, take no action

  public void deleteElements(int low,
                             int high)

delete elements and close up; if outside range take no action

  public void insertElementAt(int elem,
                              double f)

insert element and expand; if outside range, take no action

  public void insertArray(int elem,
                          RealArray f)

insert a RealArray at position elem and expand

  public void addElement(double f)

append element

  public void addArray(RealArray f)

append elements

  public RealArray getReorderedArray(IntSet idx) throws BadSubscriptException

reorder by index in IntSet; does NOT modify array

Throws: BadSubscriptException

an element of idx is outside range of this

  public IntSet inRange(RealRange r)

return index of elements within a given range

  public IntSet outOfRange(RealRange r)

return index of elements outside a given range

  public String[] getStringValues()

returns values as strings

  public String toString()

concatenates values with spaces

Overrides:

toString in class Object

  public static double[] deleteElements(double f[],
                                        int low,
                                        int hi)

delete elements (lo - > hi inclusive) in a float[] and close up; if hi >= float.length hi is reset to float.length-1.

  public static double[] copy(double f[])

copy a double[] into a new one

  public void sortAscending()

MODIFIES array to be in ascending order

  public void sortDescending()

MODIFIES array to be in ascending order

  public void reverse()

MODIFIES array to be in reverse order

  public IntSet indexSortAscending()

  public IntSet indexSortDescending()

sort array into descending order via indexes; array NOT MODIFIED

  public static void test()

  public static void main(String args[])

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