maspack.matrix

Class VectorNi

java.lang.Object

maspack.matrix.VectoriBase

maspack.matrix.VectorNi

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, Vectori, Clonable

public class VectorNi
extends VectoriBase
implements java.io.Serializable

Implements a general vector of integers. We have provided integer implementations of all methods of VectorNd for which it makes sense to do so.

These vectors can be resized, either explicitly through a call to setSize, or implicitly through operations that require the vector size to be modified.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
VectorNi() Creates a vector with an initial size of zero.
VectorNi(int size) Creates a vector of a specific size, and initializes its elements to 0.
VectorNi(int[] values) Creates a vector from an array of ints.
VectorNi(int size, int[] values) Creates a vector of a specific size, and initializes its elements from an array of values.
VectorNi(Vectori vec) Creates a new VectorNi from an existing Vectori.
VectorNi(VectorNi vec) Creates a new VectorNi from an existing one.

Method Summary

Modifier and Type	Method and Description
VectorNi	absolute() Sets the elements of this vector to their absolute values.
VectorNi	absolute(VectorNi v1) Sets the elements of this vector to the absolute value of v1.
void	add(int i, int value) Adds a value to the i-th element of this vector.
VectorNi	add(VectorNi v1) Adds this vector to v1 and places the result in this vector.
VectorNi	add(VectorNi v1, VectorNi v2) Adds vector v1 to v2 and places the result in this vector.
int	adjustSize(int inc)
void	append(int value) Appends a value to the end of this vector, increasing its size by one.
void	append(VectorNi vec) Appends the values of vec to the end of this vector, increasing its size by the size of vec.
VectorNi	clone()
boolean	equals(Vectori v1) Returns true if the elements of this vector exactly equal those of vector v1.
boolean	equals(VectorNi v1) Returns true if the elements of this vector exactly equal those of vector v1.
int	get(int i) Gets a single element of this vector.
void	get(int[] values) Copies the elements of this vector into an array of doubles.
int	get(int[] values, int idx) Copies the elements of this vector into an array of int, starting at a particular location.
int[]	getBuffer() Returns the internal buffer used to store the elements in this vector.
int	getCapacity()
void	getSubVector(int off, VectorNi v1) Gets a subset of the values of this vector, beginning at a specified offset, and places them in v1.
int	infinityNorm() Returns the infinity norm of this vector.
boolean	isFixedSize() Returns true if this vector is of fixed size.
VectorNi	max(VectorNi v) Computes the element-wise maximum of this vector and vector v and places the result in this vector.
int	maxElement() Returns the maximum element value.
VectorNi	min(VectorNi v) Computes the element-wise minimum of this vector and vector v and places the result in this vector.
int	minElement() Returns the minimum element value.
VectorNi	negate() Negates this vector in place.
VectorNi	negate(VectorNi v1) Sets this vector to the negative of v1.
double	norm() Returns the 2 norm of this vector.
double	normSquared() Returns the square of the 2 norm of this vector.
int	oneNorm() Returns the 1 norm of this vector.
void	permute(int[] permutation) Rearrange the elements of this vector according to the specified permutation, such that each element i is replaced by element permutation[i].
void	remove(int i) Removes the i-th value from this vector, decreasing its size by one.
VectorNi	scale(double s) Scales the elements of this vector by s.
VectorNi	scale(double s, VectorNi v1) Scales the elements of vector v1 by s and places the results in this vector.
VectorNi	scaledAdd(double s, VectorNi v1) Computes s v1 and adds the result to this vector.
VectorNi	scaledAdd(double s, VectorNi v1, VectorNi v2) Computes s v1 + v2 and places the result in this vector.
void	scan(ReaderTokenizer rtok) Sets the contents of this vector to values read from a ReaderTokenizer.
void	set(int[] values) Sets the elements of this vector from an array of doubles.
int	set(int[] values, int idx) Sets the elements of this vector from an array of ints, starting from a particular location.
void	set(int i, int value) Sets a single element of this vector.
void	set(VectorNi v1) Sets the size and values of this vector to those of v1.
void	setAll(int value) Sets the elements of this vector to a specific value.
void	setBuffer(int size, int[] buffer) Explicitly sets the size and internal buffer associated with this vector.
void	setCapacity(int newcap)
void	setRandom() Sets the elements of this vector to uniformly distributed random values in the range -1000 (inclusive) to 1000 (exclusive).
void	setRandom(int lower, int upper) Sets the elements of this vector to uniformly distributed random values in a specified range.
void	setRandom(int lower, int upper, java.util.Random generator) Sets the elements of this vector to uniformly distributed random values in a specified range, using a supplied random number generator.
void	setSize(int newSize) Sets the size of this vector.
void	setSubVector(int off, VectorNi v1) Sets a subset of the values of this vector, beginning at a specified offset, to the values of v1.
void	setZero() Sets the elements of this vector to zero.
int	size() Returns the number of elements in this vector.
void	sort() Sorts the contents of this vector by element value, from largest to smallest value.
void	sort(VectorNi v1) Sorts the contents of vector v1 by element value, from largest to smallest value, and places the result into this vector.
VectorNi	sub(VectorNi v1) Subtracts v1 from this vector and places the result in this vector.
VectorNi	sub(VectorNi v1, VectorNi v2) Subtracts vector v1 from v2 and places the result in this vector.
int	sum() Returns the sum of all the elements in this vector.
void	unsetBuffer() Removes an explicit buffer provided for this vector and replaces it with a default implicit buffer.

Methods inherited from class maspack.matrix.VectoriBase

getDefaultFormat, set, setDefaultFormat, toString, toString, toString, write, write

Methods inherited from class java.lang.Object

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

Constructor Detail

VectorNi

public VectorNi()

Creates a vector with an initial size of zero.

VectorNi

public VectorNi(int size)
         throws ImproperSizeException

Creates a vector of a specific size, and initializes its elements to 0. It is legal to create a vector with a size of zero.

Parameters:

size - size of the vector

Throws:

ImproperSizeException - if size is negative

VectorNi

public VectorNi(int size,
                int[] values)
         throws ImproperSizeException

Creates a vector of a specific size, and initializes its elements from an array of values.

Parameters:

size - size of the vector

values - element values for the new vector

Throws:

ImproperSizeException - if size is negative

VectorNi

public VectorNi(int[] values)

Creates a vector from an array of ints. The vector size is determined by the size of this array.

Parameters:

values - element values for the new vector

VectorNi

public VectorNi(VectorNi vec)

Creates a new VectorNi from an existing one.

Parameters:

vec - VectorNi to be copied

VectorNi

public VectorNi(Vectori vec)

Creates a new VectorNi from an existing Vectori.

Parameters:

vec - Vectori to be copied

Method Detail

getBuffer

public int[] getBuffer()

Returns the internal buffer used to store the elements in this vector. When possible, applications should access the vector elements using the various set and get methods. However, if efficiency requires it, this buffer can be used directly.

Note that the buffer may be larger than the vector. The i-th element in the vector corresponds to the i-th entry in the buffer.

If this vector is resized, then the internal buffer may change and the buffer previously returned by this routine may no longer be valid.

Returns:

internal buffer for this vector

See Also:

setBuffer(int, int[])

size

public int size()

Returns the number of elements in this vector.

Specified by:

size in interface Vectori

Specified by:

size in class VectoriBase

Returns:

number of elements

adjustSize

public int adjustSize(int inc)
               throws ImproperSizeException

Throws:

ImproperSizeException

getCapacity

public int getCapacity()

setCapacity

public void setCapacity(int newcap)

setBuffer

public void setBuffer(int size,
                      int[] buffer)

Explicitly sets the size and internal buffer associated with this vector. Any previous values will be discarded, and the vector will assume the new values presently contained within the buffer. The length of buffer must equal or exceed the specified size. The vector can continue to be resized as long as the requested sizes do not exceed the buffer size.

Parameters:

size - new vector size

buffer - explicit buffer for this vector

Throws:

ImproperSizeException - if the specified buffer is too small for the requested size

See Also:

unsetBuffer()

unsetBuffer

public void unsetBuffer()

Removes an explicit buffer provided for this vector and replaces it with a default implicit buffer. The vector retains its present size but all values are replaced with zero.

Throws:

java.lang.IllegalStateException - if this vector does not have an explicit buffer given by setBuffer

See Also:

setBuffer(int, int[])

get

public int get(int i)

Gets a single element of this vector.

Specified by:

get in interface Vectori

Specified by:

get in class VectoriBase

Parameters:

i - element index

Returns:

element value

get

public void get(int[] values)

Copies the elements of this vector into an array of doubles. The array length must be >= the size of the vector.

Specified by:

get in interface Vectori

Overrides:

get in class VectoriBase

Parameters:

values - array into which values are copied

get

public int get(int[] values,
               int idx)

Copies the elements of this vector into an array of int, starting at a particular location.

Parameters:

values - array into which values are copied

idx - starting point within values where copying should begin

Returns:

updated idx value

set

public void set(int i,
                int value)

Sets a single element of this vector.

Specified by:

set in interface Vectori

Specified by:

set in class VectoriBase

Parameters:

i - element index

value - element value

append

public void append(int value)

Appends a value to the end of this vector, increasing its size by one. If the vector's capacity (i.e., the length of the underlying array) needs to be increased, this is done by an extended amount in order to reduce the overall number of capacity increases that may be incurred by a sequence of append calls.

Parameters:

value - value to append to the end of this vector

Throws:

ImproperSizeException - if the capacity needs to be increased but the internal buffer is explicit and so cannot be increased.

append

public void append(VectorNi vec)

Appends the values of vec to the end of this vector, increasing its size by the size of vec. If the vector's capacity (i.e., the length of the underlying array) needs to be increased, this is done by an extended amount in order to reduce the overall number of capacity increases that may be incurred by a sequence of append calls.

Parameters:

vec - vector to append to the end of this vector

Throws:

ImproperSizeException - if the capacity needs to be increased but the internal buffer is explicit and so cannot be increased.

remove

public void remove(int i)

Removes the i-th value from this vector, decreasing its size by one. Indices for all values greater than i are decremented by one.

Parameters:

i - index of the value to be removed

set

public void set(int[] values)

Sets the elements of this vector from an array of doubles. If the vector has a fixed size, then the array must have a length >= the current vector size. Otherwise, the vector is resized to the array length.

Specified by:

set in interface Vectori

Overrides:

set in class VectoriBase

Parameters:

values - array from which values are copied

set

public int set(int[] values,
               int idx)

Sets the elements of this vector from an array of ints, starting from a particular location.

Parameters:

values - array into which values are copied

idx - starting point within values from which copying should begin

Returns:

updated idx value

set

public void set(VectorNi v1)

Sets the size and values of this vector to those of v1.

Parameters:

v1 - vector whose size and values are copied

getSubVector

public void getSubVector(int off,
                         VectorNi v1)

Gets a subset of the values of this vector, beginning at a specified offset, and places them in v1.

Parameters:

off - offset where copying should begin in this vector

v1 - vector returning the sub-vector values

Throws:

ImproperSizeException - if this vector is not large enough to accomodate the specified subvector

setSubVector

public void setSubVector(int off,
                         VectorNi v1)

Sets a subset of the values of this vector, beginning at a specified offset, to the values of v1.

Parameters:

off - offset where copying should begin in this vector

v1 - vector whose values are copied

Throws:

ImproperSizeException - if this vector is not large enough to accomodate the specified subvector

add

public VectorNi add(VectorNi v1,
                    VectorNi v2)
             throws ImproperSizeException

Adds vector v1 to v2 and places the result in this vector. This vector is resized if necessary.

Parameters:

v1 - left-hand vector

v2 - right-hand vector

Returns:

this vector

Throws:

ImproperSizeException - if v1 and v2 have different sizes, or if this vector needs resizing but is of fixed size

add

public VectorNi add(VectorNi v1)
             throws ImproperSizeException

Adds this vector to v1 and places the result in this vector.

Parameters:

v1 - right-hand vector

Returns:

this vector

Throws:

ImproperSizeException - if v1 has a size less than this vector

add

public void add(int i,
                int value)

Adds a value to the i-th element of this vector.

Parameters:

i - index of the element

value - value to be added

sub

public VectorNi sub(VectorNi v1,
                    VectorNi v2)
             throws ImproperSizeException

Subtracts vector v1 from v2 and places the result in this vector. This vector is resized if necessary.

Parameters:

v1 - left-hand vector

v2 - right-hand vector

Returns:

this vector

Throws:

ImproperSizeException - if v1 and v2 have different sizes, or if this vector needs resizing but is of fixed size

sub

public VectorNi sub(VectorNi v1)
             throws ImproperSizeException

Subtracts v1 from this vector and places the result in this vector.

Parameters:

v1 - right-hand vector

Returns:

this vector

Throws:

ImproperSizeException - if v1 has a size less than this vector

negate

public VectorNi negate(VectorNi v1)

Sets this vector to the negative of v1. This vector is resized if necessary.

Parameters:

v1 - vector to negate

Returns:

this vector

negate

public VectorNi negate()

Negates this vector in place.

Returns:

this vector

scale

public VectorNi scale(double s)

Scales the elements of this vector by s.

Parameters:

s - scaling factor

Returns:

this vector

scale

public VectorNi scale(double s,
                      VectorNi v1)

Scales the elements of vector v1 by s and places the results in this vector. This vector is resized if necessary.

Parameters:

s - scaling factor

v1 - vector to be scaled

Returns:

this vector

scaledAdd

public VectorNi scaledAdd(double s,
                          VectorNi v1,
                          VectorNi v2)
                   throws ImproperSizeException

Computes s v1 + v2 and places the result in this vector. This vector is resized if necessary.

Parameters:

s - scaling factor

v1 - vector to be scaled

v2 - vector to be added

Returns:

this vector

Throws:

ImproperSizeException - if v1 and v2 have different sizes

scaledAdd

public VectorNi scaledAdd(double s,
                          VectorNi v1)
                   throws ImproperSizeException

Computes s v1 and adds the result to this vector.

Parameters:

s - scaling factor

v1 - vector to be scaled and added

Returns:

this vector

Throws:

ImproperSizeException - if v1 has a size less than this vector

isFixedSize

public boolean isFixedSize()

Returns true if this vector is of fixed size. In the present implementation, VectorNi objects always have variable size, and so this routine always returns false.

Specified by:

isFixedSize in interface Vectori

Overrides:

isFixedSize in class VectoriBase

Returns:

true if this vector is of fixed size

See Also:

setSize(int)

setSize

public void setSize(int newSize)
             throws ImproperSizeException

Sets the size of this vector. This operation may enlarge the internal buffer associated with this vector, invalidating buffers previously returned by getBuffer.

If a vector is resized, then previous element values which are still within the new vector dimension are preserved. Other (new) element values are undefined.

Specified by:

setSize in interface Vectori

Overrides:

setSize in class VectoriBase

Parameters:

newSize - new vector size

Throws:

ImproperSizeException - if this vector has an explicit internal buffer and that buffer is too small for the requested size

See Also:

Vectori.isFixedSize()

norm

public double norm()

Returns the 2 norm of this vector. This is the square root of the sum of the squares of the elements.

Specified by:

norm in interface Vectori

Overrides:

norm in class VectoriBase

Returns:

vector 2 norm

normSquared

public double normSquared()

Returns the square of the 2 norm of this vector. This is the sum of the squares of the elements.

Specified by:

normSquared in interface Vectori

Overrides:

normSquared in class VectoriBase

Returns:

square of the 2 norm

oneNorm

public int oneNorm()

Returns the 1 norm of this vector. This is the sum of the absolute values of the elements.

Specified by:

oneNorm in interface Vectori

Overrides:

oneNorm in class VectoriBase

Returns:

vector 1 norm

infinityNorm

public int infinityNorm()

Returns the infinity norm of this vector. This is the maximum absolute value over all elements.

Specified by:

infinityNorm in interface Vectori

Overrides:

infinityNorm in class VectoriBase

Returns:

vector infinity norm

maxElement

public int maxElement()

Returns the maximum element value.

Specified by:

maxElement in interface Vectori

Overrides:

maxElement in class VectoriBase

Returns:

maximal element

minElement

public int minElement()

Returns the minimum element value.

Specified by:

minElement in interface Vectori

Overrides:

minElement in class VectoriBase

Returns:

minimal element

equals

public boolean equals(Vectori v1)

Returns true if the elements of this vector exactly equal those of vector v1. If the vectors have different sizes, false is returned.

Specified by:

equals in interface Vectori

Overrides:

equals in class VectoriBase

Parameters:

v1 - vector to compare with

Returns:

false if the vectors are not equal or have different sizes

equals

public boolean equals(VectorNi v1)

Returns true if the elements of this vector exactly equal those of vector v1.

Parameters:

v1 - vector to compare with

Returns:

false if the vectors are not equal or have different sizes

sum

public int sum()

Returns the sum of all the elements in this vector.

Returns:

sum of all the elements

setZero

public void setZero()

Sets the elements of this vector to zero.

setAll

public void setAll(int value)

Sets the elements of this vector to a specific value.

absolute

public VectorNi absolute()

Sets the elements of this vector to their absolute values.

Returns:

this vector

absolute

public VectorNi absolute(VectorNi v1)

Sets the elements of this vector to the absolute value of v1. This vector is resized if necessary.

Parameters:

v1 - vector to take the absolute value of

Returns:

this vector

Throws:

ImproperSizeException - if this vector needs resizing but is of fixed size

sort

public void sort()

Sorts the contents of this vector by element value, from largest to smallest value.

sort

public void sort(VectorNi v1)

Sorts the contents of vector v1 by element value, from largest to smallest value, and places the result into this vector.

Parameters:

v1 - vector to sort

max

public VectorNi max(VectorNi v)
             throws ImproperSizeException

Computes the element-wise maximum of this vector and vector v and places the result in this vector.

Parameters:

v - vector to compare with

Returns:

this vector

Throws:

ImproperSizeException - if this vector and v have different sizes

min

public VectorNi min(VectorNi v)
             throws ImproperSizeException

Computes the element-wise minimum of this vector and vector v and places the result in this vector.

Parameters:

v - vector to compare with

Returns:

this vector

Throws:

ImproperSizeException - if this vector and v have different sizes

clone

public VectorNi clone()

Specified by:

clone in interface Clonable

Overrides:

clone in class VectoriBase

permute

public void permute(int[] permutation)

Rearrange the elements of this vector according to the specified permutation, such that each element i is replaced by element permutation[i].

Parameters:

permutation - describes the element exchanges

Throws:

ImproperSizeException - if the length of permutation is less than the size of this vector.

setRandom

public void setRandom()

Sets the elements of this vector to uniformly distributed random values in the range -1000 (inclusive) to 1000 (exclusive).

setRandom

public void setRandom(int lower,
                      int upper)

Sets the elements of this vector to uniformly distributed random values in a specified range.

Parameters:

lower - lower random value (inclusive)

upper - upper random value (exclusive)

setRandom

public void setRandom(int lower,
                      int upper,
                      java.util.Random generator)

Sets the elements of this vector to uniformly distributed random values in a specified range, using a supplied random number generator.

Parameters:

lower - lower random value (inclusive)

upper - upper random value (exclusive)

generator - random number generator

scan

public void scan(ReaderTokenizer rtok)
          throws java.io.IOException

Sets the contents of this vector to values read from a ReaderTokenizer. The input should consist of a sequence of integers, separated by white space and optionally surrounded by square brackets [ ].

If the input is not surrounded by square brackets, then the number of values should equal the current size of this vector.

If the input is surrounded by square brackets, then all values up to the closing bracket are read, and this vector will be resized to resulting number of values. For example,

 [ 1 4 5 3 ]
 

defines a vector of size 4.

Specified by:

scan in interface Vectori

Overrides:

scan in class VectoriBase

Parameters:

rtok - Tokenizer from which vector values are read. Number parsing should be enabled.

Throws:

ImproperSizeException - if this vector has a fixed size which is incompatible with the input

java.io.IOException