Class SparseVector

A one-dimensional vector of double values, optimised for the case where many of the elements share a common value (which need not be zero).

Inheritance
Object
Vector
SparseVector
ApproximateSparseVector
Inherited Members
Namespace: Microsoft.ML.Probabilistic.Math
Assembly: Microsoft.ML.Probabilistic.dll
Syntax
[Serializable]
[DataContract]
public class SparseVector : Vector, IReadOnlyList<double>, IReadOnlyCollection<double>, SettableToPower<Vector>, SettableToProduct<Vector>, SettableToProduct<Vector, Vector>, SettableToWeightedSum<Vector>, ISparseList<double>, IList<double>, ICollection<double>, ISparseEnumerable<double>, IEnumerable<double>, IEnumerable, ICloneable, CanSetAllElementsTo<double>, SettableTo<Vector>

Constructors

SparseVector()

Constructs a zero vector with the given number of elements.

Declaration
protected SparseVector()

SparseVector(SparseVector)

Copy constructor.

Declaration
protected SparseVector(SparseVector that)
Parameters
Type Name Description
SparseVector that

the vector to copy into this new vector

SparseVector(IList<Double>)

Creates a sparse vector from a list of doubles.

Declaration
protected SparseVector(IList<double> dlist)
Parameters
Type Name Description
IList<Double> dlist

the list of doubles

SparseVector(Int32)

Constructs a zero vector with the given number of elements.

Declaration
protected SparseVector(int count)
Parameters
Type Name Description
Int32 count

Number of elements to allocate (>= 0).

SparseVector(Int32, Double)

Constructs a vector of a given length and assigns all elements the given value.

Declaration
protected SparseVector(int count, double commonValue)
Parameters
Type Name Description
Int32 count

Number of elements to allocate (>= 0).
Double commonValue

The value to assign to all elements.

SparseVector(Int32, Double, List<ValueAtIndex<Double>>)

Constructs a vector of a given length and assigns all elements the given value, except for the specified list of sparse values. This list is stored internally as is so MUST be sorted by index and must not be modified externally.

Declaration
protected SparseVector(int count, double commonValue, List<ValueAtIndex<double>> sortedSparseValues)
Parameters
Type Name Description
Int32 count

Number of elements to allocate (>= 0).
Double commonValue

The value to assign to all elements.
List<ValueAtIndex<Double>> sortedSparseValues

The list of sparse values, which must be sorted by index.

Properties

CommonValue

The value of all elements not mentioned explicitly as sparse values.

Declaration
[DataMember]
public double CommonValue { get; protected set; }
Property Value
Type Description
Double

Count

The number of elements in this vector

Declaration
public override int Count { get; protected set; }
Property Value
Type Description
Int32
Overrides

HasCommonElements

Returns true if there is at least one element which has the common value.

Declaration
public bool HasCommonElements { get; }
Property Value
Type Description
Boolean

Item[Int32]

Gets or sets an element at a given index.

Declaration
public override double this[int index] { get; set; }
Parameters
Type Name Description
Int32 index

The index of an element.
Property Value
Type Description
Double

The element at a given index.
Overrides

SparseCount

The number of elements not equal to the common value

Declaration
public int SparseCount { get; }
Property Value
Type Description
Int32

SparseValues

A list of the value and indices of elements which may not have the common value (although they are not precluded from doing so). This list is kept sorted by index to allow efficient operations on the sparse vector.

Declaration
[DataMember]
public List<ValueAtIndex<double>> SparseValues { get; protected set; }
Property Value
Type Description
List<ValueAtIndex<Double>>

Methods

Add(Double)

Declaration
public void Add(double item)
Parameters
Type Name Description
Double item

All(Converter<Double, Boolean>)

Tests if all elements in the vector satisfy the specified condition.

Declaration
public override bool All(Converter<double, bool> fun)
Parameters
Type Name Description
Converter<Double, Boolean> fun
Returns
Type Description
Boolean
Overrides

Any(SparseVector, Func<Double, Double, Boolean>)

Test if any corresponding elements in this and that vector satisfy a condition

Declaration
public bool Any(SparseVector that, Func<double, double, bool> fun)
Parameters
Type Name Description
SparseVector that
Func<Double, Double, Boolean> fun
Returns
Type Description
Boolean

Any(Vector, Func<Double, Double, Boolean>)

Test if any corresponding elements in this and that vector satisfy a condition

Declaration
public override bool Any(Vector that, Func<double, double, bool> fun)
Parameters
Type Name Description
Vector that
Func<Double, Double, Boolean> fun
Returns
Type Description
Boolean
Overrides

Any(Converter<Double, Boolean>)

Tests if any elements in the vector satisfy the specified condition.

Declaration
public override bool Any(Converter<double, bool> fun)
Parameters
Type Name Description
Converter<Double, Boolean> fun
Returns
Type Description
Boolean
Overrides

Append(Vector)

Returns a new vector which appends a second vector to this vector

Declaration
public override Vector Append(Vector second)
Parameters
Type Name Description
Vector second

Second vector
Returns
Type Description
Vector
Overrides
Remarks

If the second vector is dense, or if the common values for the two vectors are different, then the result becomes dense

Append(Double)

Appends an item to a vector - returns a new sparse vector

Declaration
public override Vector Append(double item)
Parameters
Type Name Description
Double item
Returns
Type Description
Vector
Overrides

AsSparseVector(IList<Double>)

Converts the supplied list of doubles to a sparse vector, or does nothing if it is already a sparse vector.

Declaration
public static SparseVector AsSparseVector(IList<double> iList)
Parameters
Type Name Description
IList<Double> iList
Returns
Type Description
SparseVector

A sparse vector containing the list of doubles

Clear()

Declaration
public void Clear()

Clone()

Clones this vector - return as a vector

Declaration
public override Vector Clone()
Returns
Type Description
Vector
Overrides

Constant(Int32, Double)

Create a sparse vector of given length with elements all equal to a specified value

Declaration
public static SparseVector Constant(int count, double value)
Parameters
Type Name Description
Int32 count

Number of elements in vector
Double value

value for each element
Returns
Type Description
SparseVector

Contains(Double)

Returns true if the Vector contains the specified value

Declaration
public override bool Contains(double value)
Parameters
Type Name Description
Double value

The value to test for
Returns
Type Description
Boolean
Overrides

Copy(Vector)

Creator a sparse vector as a copy of another vector (which may not be sparse)

Declaration
public static SparseVector Copy(Vector that)
Parameters
Type Name Description
Vector that

The source vector - can be dense or sparse
Returns
Type Description
SparseVector

CopyTo(Double[], Int32)

Copies this vector to the given array starting at the specified index in the target array

Declaration
public override void CopyTo(double[] array, int index)
Parameters
Type Name Description
Double[] array

The target array
Int32 index

The start index in the target array
Overrides

CountAll(Converter<Double, Boolean>)

Returns the number of elements in the vector which satisfy a given condition.

Declaration
public override int CountAll(Converter<double, bool> fun)
Parameters
Type Name Description
Converter<Double, Boolean> fun

The condition for the elements to satisfy.
Returns
Type Description
Int32

The number of elements in the vector which satisfy the condition.
Overrides

Equals(Object)

Determines object equality.

Declaration
public override bool Equals(object obj)
Parameters
Type Name Description
Object obj

Another (vector) object.
Returns
Type Description
Boolean

True if equal.
Overrides

FindAll(Converter<Double, Boolean>)

Returns an enumeration over the indices of all elements which satisfy the specified condition. Indices are returned in sorted order.

Declaration
public override IEnumerable<ValueAtIndex<double>> FindAll(Converter<double, bool> fun)
Parameters
Type Name Description
Converter<Double, Boolean> fun

A function to check if the condition is satisfied.
Returns
Type Description
IEnumerable<ValueAtIndex<Double>>

An enumeration over the indices and values of all the elements which satisfy the specified condition.
Overrides

FindFirstIndex(Converter<Double, Boolean>)

Returns the index of the first element that satisfies a given condition.

Declaration
public override int FindFirstIndex(Converter<double, bool> fun)
Parameters
Type Name Description
Converter<Double, Boolean> fun

The condition for the element to satisfy.
Returns
Type Description
Int32

The zero-based index of the first occurrence of an element that matches the conditions defined by match, if found; otherwise, –1.
Overrides

FindLastIndex(Converter<Double, Boolean>)

Returns the index of the last element that satisfies a given condition.

Declaration
public override int FindLastIndex(Converter<double, bool> fun)
Parameters
Type Name Description
Converter<Double, Boolean> fun

The condition for the element to satisfy.
Returns
Type Description
Int32

The last index.
Overrides

FromArray(Double[])

Constructs a sparse vector from a dense array.

Declaration
public static SparseVector FromArray(params double[] data)
Parameters
Type Name Description
Double[] data

1D array of elements.
Returns
Type Description
SparseVector
Remarks

The array data is copied into new storage. The size of the vector is taken from the array.

FromArray(Int32, Double[], Int32)

Constructs a vector from part of an array.

Declaration
public static SparseVector FromArray(int count, double[] data, int start)
Parameters
Type Name Description
Int32 count

The number of elements in the vector.
Double[] data

Storage for the vector elements.
Int32 start

The starting index in the array for the vector elements.
Returns
Type Description
SparseVector
Remarks

Throws an exception if Data is null, start < 0, or count < 0.

FromSparseValues(Int32, Double, List<ValueAtIndex<Double>>)

Constructs a sparse vector from a sorted list of sparse elements.

Declaration
[Construction(new string[]{"Count", "CommonValue", "SparseValues"})]
public static SparseVector FromSparseValues(int count, double commonValue, List<ValueAtIndex<double>> sortedSparseValues)
Parameters
Type Name Description
Int32 count

Count for result
Double commonValue

Common value
List<ValueAtIndex<Double>> sortedSparseValues

Sorted list of sparse elements
Returns
Type Description
SparseVector

GetEnumerator()

Gets a typed enumerator which yields the vector elements

Declaration
public override IEnumerator<double> GetEnumerator()
Returns
Type Description
IEnumerator<Double>
Overrides

GetFirstCommonIndex()

Gets the dense index of the first common element.

Declaration
public int GetFirstCommonIndex()
Returns
Type Description
Int32

Returns the dense index of the first common element or -1 if there are no common elements

GetHashCode()

Gets a hash code for the instance.

Declaration
public override int GetHashCode()
Returns
Type Description
Int32

The code.
Overrides

GetSparseEnumerator()

Returns a sparse enumerator

Declaration
public ISparseEnumerator<double> GetSparseEnumerator()
Returns
Type Description
ISparseEnumerator<Double>

GetSparseIndex(Int32)

Gets the index into the sparse values array corresponding to an element index. If there is no sparse value at that index, returns the binary complement of the index in the sparse array where such an element should be inserted to retain the sort order of the sparse array.

Declaration
protected int GetSparseIndex(int index)
Parameters
Type Name Description
Int32 index
Returns
Type Description
Int32

GreaterThan(Vector)

Tests if this vector is strictly greater than a second vector.

Declaration
public override bool GreaterThan(Vector that)
Parameters
Type Name Description
Vector that

The value to test against.
Returns
Type Description
Boolean

True if each element is strictly greater than the corresponding element of that.
Overrides

GreaterThanOrEqual(Vector)

Tests if this vector is than or equal to a second vector.

Declaration
public override bool GreaterThanOrEqual(Vector that)
Parameters
Type Name Description
Vector that

The value to test against.
Returns
Type Description
Boolean

True if each element is greater than or equal to the corresponding element of that.
Overrides

IndexAtCumulativeSum(Double)

Returns the index of the first element at which the sum of all elements so far is greater than a particular value. Useful for finding the median of a Discrete distribution.

Declaration
public override int IndexAtCumulativeSum(double targetSum)
Parameters
Type Name Description
Double targetSum

The sum of interest
Returns
Type Description
Int32

The index of the element where targetSum is exceeded or -1 if targetSum cannot be exceeded.
Overrides

IndexOf(Double)

Returns the index of the first occurence of the given value in the array. Returns -1 if the value is not in the array

Declaration
public override int IndexOf(double item)
Parameters
Type Name Description
Double item

The item to check for
Returns
Type Description
Int32

Its index in the array
Overrides

IndexOfMaximum()

Returns the index of the maximum element.

Declaration
public override int IndexOfMaximum()
Returns
Type Description
Int32

The index of the maximum element.
Overrides

IndexOfMinimum()

Returns the index of the minimum element.

Declaration
public override int IndexOfMinimum()
Returns
Type Description
Int32

The index of the minimum element.
Overrides

Inner(SparseVector)

Returns the inner product of this sparse vector with another sparse vector.

Declaration
public double Inner(SparseVector that)
Parameters
Type Name Description
SparseVector that

Second vector, which must have the same size as this.
Returns
Type Description
Double

Their inner product.

Inner(SparseVector, Converter<Double, Double>)

Returns the inner product of this sparse vector with a function of a second sparse vector.

Declaration
public double Inner(SparseVector that, Converter<double, double> fun)
Parameters
Type Name Description
SparseVector that

Second vector, which must have the same size as this.
Converter<Double, Double> fun

Function to convert the elements of the second vector
Returns
Type Description
Double

Their inner product.

Inner(Vector)

Returns the inner product of this vector with another vector.

Declaration
public override double Inner(Vector that)
Parameters
Type Name Description
Vector that

Second vector, which must have the same size as this.
Returns
Type Description
Double

Their inner product.
Overrides

Inner(Vector, Converter<Double, Double>)

Returns the inner product of this vector with a function of a second vector.

Declaration
public override double Inner(Vector that, Converter<double, double> fun)
Parameters
Type Name Description
Vector that

Second vector, which must have the same size as this.
Converter<Double, Double> fun

Function to convert the elements of the second vector
Returns
Type Description
Double

Their inner product.
Overrides

Inner(Converter<Double, Double>, SparseVector, Converter<Double, Double>)

Returns the inner product of a function of this sparse vector with a function of a second sparse vector.

Declaration
public double Inner(Converter<double, double> thisFun, SparseVector that, Converter<double, double> thatFun)
Parameters
Type Name Description
Converter<Double, Double> thisFun

Function to convert the elements of this vector
SparseVector that

Second vector, which must have the same size as this.
Converter<Double, Double> thatFun

Function to convert the elements of that vector
Returns
Type Description
Double

Their inner product.

Inner(Converter<Double, Double>, Vector, Converter<Double, Double>)

Returns the inner product of a function of this vector with a function of a second vector.

Declaration
public override double Inner(Converter<double, double> thisFun, Vector that, Converter<double, double> thatFun)
Parameters
Type Name Description
Converter<Double, Double> thisFun

Function to convert the elements of this vector
Vector that

Second vector, which must have the same size as this.
Converter<Double, Double> thatFun

Function to convert the elements of that vector
Returns
Type Description
Double

Their inner product.
Overrides

LessThan(Vector)

Tests if this vector is strictly less than a second vector.

Declaration
public override bool LessThan(Vector that)
Parameters
Type Name Description
Vector that

The value to test against.
Returns
Type Description
Boolean

True if each element is strictly less than the corresponding element of that.
Overrides

LessThanOrEqual(Vector)

Tests if this vector is less than or equal to a second vector.

Declaration
public override bool LessThanOrEqual(Vector that)
Parameters
Type Name Description
Vector that

The value to test against.
Returns
Type Description
Boolean

True if each element is strictly less than or equal to the corresponding element of that.
Overrides

LogSumExp()

Returns the log of the sum of exponentials of the elements of the vector computed to high accuracy

Declaration
public override double LogSumExp()
Returns
Type Description
Double
Overrides

Max()

Returns the maximum of the elements in the vector

Declaration
public override double Max()
Returns
Type Description
Double
Overrides

Max(Converter<Double, Double>)

Returns the maximum of a function of the elements in the vector

Declaration
public override double Max(Converter<double, double> fun)
Parameters
Type Name Description
Converter<Double, Double> fun

Conversion function
Returns
Type Description
Double
Overrides

MaxDiff(Vector)

Returns the maximum absolute difference between this vector and another vector.

Declaration
public override double MaxDiff(Vector that)
Parameters
Type Name Description
Vector that

The second vector.
Returns
Type Description
Double

max(abs(this[i] - that[i])). Matching infinities or NaNs do not count.
If this and that are not the same size, returns infinity.
Overrides
Remarks

This routine is typically used instead of Equals, since Equals is susceptible to roundoff errors.

MaxDiff(Vector, Double)

Returns the maximum relative difference between this vector and another.

Declaration
public override double MaxDiff(Vector that, double rel)
Parameters
Type Name Description
Vector that

The second vector.
Double rel

An offset to avoid division by zero.
Returns
Type Description
Double

max(abs(this[i] - that[i])/(abs(this[i]) + rel)). Matching infinities or NaNs do not count.
If this and that are not the same size, returns infinity.
Overrides
Remarks

This routine is typically used instead of Equals, since Equals is susceptible to roundoff errors.

Median()

Returns the median of all elements.

Declaration
public override double Median()
Returns
Type Description
Double
Overrides

Min()

Returns the minimum of the elements in the vector

Declaration
public override double Min()
Returns
Type Description
Double
Overrides

Min(Converter<Double, Double>)

Returns the minimum of the elements in the vector

Declaration
public override double Min(Converter<double, double> fun)
Parameters
Type Name Description
Converter<Double, Double> fun

Conversion function
Returns
Type Description
Double
Overrides

Outer(SparseVector)

Returns the outer product of this sparse vector with another sparse vector.

Declaration
public Matrix Outer(SparseVector that)
Parameters
Type Name Description
SparseVector that

Second vector.
Returns
Type Description
Matrix

Their outer product.

Outer(Vector)

Returns the outer product of this vector with another vector.

Declaration
public override Matrix Outer(Vector that)
Parameters
Type Name Description
Vector that

Second vector.
Returns
Type Description
Matrix

Their outer product.
Overrides

Reduce(Double, SparseVector, SparseVector, Func<Double, Double, Double, Double, Double>)

Reduce method. Operates on this vector and two other vectors

Declaration
public double Reduce(double initial, SparseVector a, SparseVector b, Func<double, double, double, double, double> fun)
Parameters
Type Name Description
Double initial

Initial value
SparseVector a

A second vector
SparseVector b

A third vector
Func<Double, Double, Double, Double, Double> fun

Reduction function
Returns
Type Description
Double

Reduce(Double, SparseVector, Func<Double, Double, Double, Double>)

Reduce method. Operates on this vector and that vector

Declaration
public double Reduce(double initial, SparseVector that, Func<double, double, double, double> fun)
Parameters
Type Name Description
Double initial

Initial value
SparseVector that

A second vector
Func<Double, Double, Double, Double> fun

Reduction function taking partial result, current element, and current element of that
Returns
Type Description
Double

Reduce(Double, Vector, Func<Double, Double, Double, Double>)

Reduce method. Operates on this vector and that vector

Declaration
public override double Reduce(double initial, Vector that, Func<double, double, double, double> fun)
Parameters
Type Name Description
Double initial

Initial value
Vector that

A second vector
Func<Double, Double, Double, Double> fun

Reduction function taking partial result, current element, and current element of that
Returns
Type Description
Double
Overrides

Reduce(Double, Func<Double, Double, Double>)

Reduce method. Operates on this vector

Declaration
public override double Reduce(double initial, Func<double, double, double> fun)
Parameters
Type Name Description
Double initial

Initial value
Func<Double, Double, Double> fun

Reduction function taking partial result and current element
Returns
Type Description
Double
Overrides

Reduce<TRes>(TRes, Func<TRes, Double, TRes>, Func<TRes, Double, Int32, TRes>)

Reduce method which can take advantage of sparse structure. Operates on this list

Declaration
public TRes Reduce<TRes>(TRes initial, Func<TRes, double, TRes> fun, Func<TRes, double, int, TRes> repeatedFun)
Parameters
Type Name Description
TRes initial

Initial value
Func<TRes, Double, TRes> fun

Reduction function taking partial result and current element
Func<TRes, Double, Int32, TRes> repeatedFun

Function which computes the reduction function applied multiple times
Returns
Type Description
TRes
Type Parameters
Name Description
TRes
Remarks

This method does not take advantage of this list's sparseness.

Reduce<TRes, T1>(TRes, ISparseEnumerable<T1>, Func<TRes, Double, T1, TRes>, Func<TRes, Double, T1, Int32, TRes>)

Reduce method which can take advantage of sparse structure. Operates on this list and another sparse collection

Declaration
public TRes Reduce<TRes, T1>(TRes initial, ISparseEnumerable<T1> that, Func<TRes, double, T1, TRes> fun, Func<TRes, double, T1, int, TRes> repeatedFun)
Parameters
Type Name Description
TRes initial

Initial value
ISparseEnumerable<T1> that

The other sparse collection
Func<TRes, Double, T1, TRes> fun

Reduction function taking partial result and current element
Func<TRes, Double, T1, Int32, TRes> repeatedFun

Function which computes the reduction function applied multiple times
Returns
Type Description
TRes
Type Parameters
Name Description
TRes
T1

Reduce<TRes, T1, T2>(TRes, ISparseEnumerable<T1>, ISparseEnumerable<T2>, Func<TRes, Double, T1, T2, TRes>, Func<TRes, Double, T1, T2, Int32, TRes>)

Reduce method which can take advantage of sparse structure. Operates on this list and two other sparse collections

Declaration
public TRes Reduce<TRes, T1, T2>(TRes initial, ISparseEnumerable<T1> b, ISparseEnumerable<T2> c, Func<TRes, double, T1, T2, TRes> fun, Func<TRes, double, T1, T2, int, TRes> repeatedFun)
Parameters
Type Name Description
TRes initial

Initial value
ISparseEnumerable<T1> b

A second sparse collection
ISparseEnumerable<T2> c

A third sparse collection
Func<TRes, Double, T1, T2, TRes> fun

Reduction function taking partial result and current element
Func<TRes, Double, T1, T2, Int32, TRes> repeatedFun

Function which computes the reduction function applied multiple times
Returns
Type Description
TRes
Type Parameters
Name Description
TRes
T1
T2

Remove(Double)

Declaration
public bool Remove(double item)
Parameters
Type Name Description
Double item
Returns
Type Description
Boolean

Scale(Double)

Multiplies this vector by a scalar.

Declaration
public override void Scale(double scale)
Parameters
Type Name Description
Double scale

The scalar.
Overrides
Remarks

this receives the product. This method is a synonym for SetToProduct(this, scale)

SetAllElementsTo(Double)

Sets all elements to a given value.

Declaration
public override void SetAllElementsTo(double value)
Parameters
Type Name Description
Double value

The new value.
Overrides

SetSubvector(Int32, Vector)

Set a subvector of this sparse vector to another vector. The common value is not changed

Declaration
public override void SetSubvector(int startIndex, Vector that)
Parameters
Type Name Description
Int32 startIndex

The index of the first element of this to copy to.
Vector that

A vector whose length is at most this.Count - startIndex.
Overrides

SetTo(SparseVector)

Copies values from a sparse vector to this sparse vector.

Declaration
public virtual void SetTo(SparseVector that)
Parameters
Type Name Description
SparseVector that

SetTo(Vector)

Copies values from a Vector to this vector.

Declaration
public override void SetTo(Vector that)
Parameters
Type Name Description
Vector that
Overrides
Remarks

The source vector can be dense, in which case the minimum value is used as the common value.

SetTo(IEnumerable<Double>)

Copies values from an Enumerable to this vector

Declaration
public override void SetTo(IEnumerable<double> that)
Parameters
Type Name Description
IEnumerable<Double> that
Overrides

SetTo(IList<Double>)

Copies values from a list of doubles which must have the same size as this vector. The 'common value' is set to the minimum value of the list.

Declaration
public virtual void SetTo(IList<double> dlist)
Parameters
Type Name Description
IList<Double> dlist

SetTo(IList<Double>, Double)

Copies values from a list of doubles which must have the same size as this vector, using the specified common value.

Declaration
public virtual void SetTo(IList<double> dlist, double commonValue)
Parameters
Type Name Description
IList<Double> dlist

List of doubles
Double commonValue

Common value

SetTo(Double[])

Copies values from an array. The minimum value is used as the common value

Declaration
public override void SetTo(double[] values)
Parameters
Type Name Description
Double[] values

An array whose length matches this.Count.
Overrides

SetToDiagonal(Matrix)

Sets this vector to the diagonal of a matrix.

Declaration
public override void SetToDiagonal(Matrix m)
Parameters
Type Name Description
Matrix m

A matrix with Rows==Cols==this.Count.
Overrides

SetToFunction(SparseVector, SparseVector, Func<Double, Double, Double>)

Sets the elements of this sparse vector to a function of the elements of two other sparse vectors

Declaration
public virtual SparseVector SetToFunction(SparseVector a, SparseVector b, Func<double, double, double> fun)
Parameters
Type Name Description
SparseVector a

The first vector
SparseVector b

The second vector
Func<Double, Double, Double> fun

The function which maps two doubles to a double
Returns
Type Description
SparseVector
Remarks

Assumes the vectors are compatible

SetToFunction(SparseVector, Converter<Double, Double>)

Sets the elements of this sparse vector to a function of the elements of another sparse vector

Declaration
public virtual SparseVector SetToFunction(SparseVector that, Converter<double, double> fun)
Parameters
Type Name Description
SparseVector that

The other vector
Converter<Double, Double> fun

The function which maps doubles to doubles
Returns
Type Description
SparseVector
Remarks

Assumes the vectors are compatible

SetToFunction(Vector, Vector, Func<Double, Double, Double>)

Sets the elements of this vector to a function of the elements of two vectors

Declaration
public override Vector SetToFunction(Vector a, Vector b, Func<double, double, double> fun)
Parameters
Type Name Description
Vector a

The first vector
Vector b

The second vector
Func<Double, Double, Double> fun

The function which maps two doubles to a double
Returns
Type Description
Vector
Overrides
Remarks

Assumes the vectors are compatible

SetToFunction(Vector, Converter<Double, Double>)

Sets the elements of this vector to a function of the elements of a given vector

Declaration
public override Vector SetToFunction(Vector that, Converter<double, double> fun)
Parameters
Type Name Description
Vector that

The given vector
Converter<Double, Double> fun

The function which maps doubles to doubles
Returns
Type Description
Vector
Overrides
Remarks

Assumes the vectors are compatible

SetToFunctionInPlace(SparseVector, Func<Double, Double, Double>)

Sets the elements of this sparse vector to a function of the elements of this sparse vector and another sparse vectors x = fun(x,b)

Declaration
public virtual SparseVector SetToFunctionInPlace(SparseVector b, Func<double, double, double> fun)
Parameters
Type Name Description
SparseVector b

The second vector
Func<Double, Double, Double> fun

The function which maps two doubles to a double
Returns
Type Description
SparseVector
Remarks

Assumes the vectors are compatible

SetToSubarray(Double[], Int32)

Copies values from an array. The minimum is used as the common value

Declaration
public override void SetToSubarray(double[] values, int startIndex)
Parameters
Type Name Description
Double[] values

An array whose length is at least this.Count + startIndex.
Int32 startIndex

The index of the first value in values to copy.
Overrides

SetToSubvector(SparseVector, Int32)

Copies values from a sparse vector. The common value is set to the common value from the source vector.

Declaration
public virtual void SetToSubvector(SparseVector that, int startIndex)
Parameters
Type Name Description
SparseVector that

A vector whose length is at least this.Count + startIndex.
Int32 startIndex

The index of the first value in that to copy.

SetToSubvector(Vector, Int32)

Copies values from a vector. If the source vector is sparse, then the common value is set to the common value from the source vector. If the source vector is dense, then the common value is set to the minimum of the data in the source vector

Declaration
public override void SetToSubvector(Vector that, int startIndex)
Parameters
Type Name Description
Vector that

A vector whose length is at least this.Count + startIndex.
Int32 startIndex

The index of the first value in that to copy.
Overrides

Subvector(Int32, Int32)

Create a subvector of this sparse vector.

Declaration
public override Vector Subvector(int startIndex, int count)
Parameters
Type Name Description
Int32 startIndex
Int32 count
Returns
Type Description
Vector
Overrides

Sum()

Returns the sum of all elements.

Declaration
public override double Sum()
Returns
Type Description
Double
Overrides

Sum(Converter<Double, Double>)

Returns the sum of a function of all elements.

Declaration
public override double Sum(Converter<double, double> fun)
Parameters
Type Name Description
Converter<Double, Double> fun

Conversion function
Returns
Type Description
Double
Overrides

Sum(Converter<Double, Double>, SparseVector, Converter<Double, Boolean>)

Returns the sum of a function of this sparse vector filtered by a function of a second sparse vector.

Declaration
public double Sum(Converter<double, double> fun, SparseVector that, Converter<double, bool> cond)
Parameters
Type Name Description
Converter<Double, Double> fun

Function to convert the elements of this vector
SparseVector that

Second vector, which must have the same size as this.
Converter<Double, Boolean> cond

Function to convert the elements of that vector to give the filter condition
Returns
Type Description
Double

The filtered and mapped sum

Sum(Converter<Double, Double>, Vector, Converter<Double, Boolean>)

Returns the sum of a function of this vector filtered by a function of a second vector.

Declaration
public override double Sum(Converter<double, double> fun, Vector that, Converter<double, bool> cond)
Parameters
Type Name Description
Converter<Double, Double> fun

Function to convert the elements of this vector
Vector that

Second vector, which must have the same size as this.
Converter<Double, Boolean> cond

Function to convert the elements of that vector to give the filter condition
Returns
Type Description
Double

The filtered and mapped sum
Overrides

SumI()

Returns the sum of over zero-based index times element.

Declaration
public override double SumI()
Returns
Type Description
Double
Overrides

SumISq()

Returns the sum of over square of index^2 times element.

Declaration
public override double SumISq()
Returns
Type Description
Double
Overrides

ToArray()

Converts this sparse vector to an array of doubles

Declaration
public override double[] ToArray()
Returns
Type Description
Double[]
Overrides

ToString(String, String)

String representation of vector with a specified format and delimiter

Declaration
public override string ToString(string format, string delimiter)
Parameters
Type Name Description
String format

Format of each element value
String delimiter

Delimiter between sparse elements
Returns
Type Description
String

A string
Overrides

ToVector()

Converts this sparse vector to an ordinary non-sparse vector

Declaration
public Vector ToVector()
Returns
Type Description
Vector

Zero(Int32)

Create a sparse vector of given length with elements all 0.0

Declaration
public static SparseVector Zero(int count)
Parameters
Type Name Description
Int32 count

Number of elements in vector
Returns
Type Description
SparseVector

Explicit Interface Implementations

IEnumerable.GetEnumerator()

Gets an enumerator which yields the vector elements

Declaration
IEnumerator IEnumerable.GetEnumerator()
Returns
Type Description
IEnumerator

ICloneable.Clone()

Clones this vector - return as an object

Declaration
object ICloneable.Clone()
Returns
Type Description
Object

Implements

Extension Methods