base

package
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 Go to latest Published: Aug 10, 2014 License: MIT Imports: 18 Imported by: 0

Documentation

Overview

Package base provides base interfaces for GoLearn objects to implement. It also provides a raw base for those objects.

Index

Constants

View Source 
const (
	// CategoricalType is for Attributes which represent values distinctly.
	CategoricalType = iota
	// Float64Type should be replaced with a FractionalNumeric type [DEPRECATED].
	Float64Type
	BinaryType
)

Variables

View Source 
var Logger *log.Logger = log.New(os.Stdout, "", 0)

Logger is the default logger for the entire golearn package. It writes to stdout and has no prefix and no flags.

Functions

func DecomposeOnAttributeValues 

func DecomposeOnAttributeValues(inst FixedDataGrid, at Attribute) map[string]FixedDataGrid

DecomposeOnAttributeValues divides the instance set depending on the value of a given Attribute, constructs child instances, and returns them in a map keyed on the string value of that Attribute.

IMPORTANT: calls panic() if the AttributeSpec of at cannot be determined.

func GetClass 

func GetClass(from DataGrid, row int) string

GetClass is a shortcut for returning the string value of the current class on a given row.

IMPORTANT: GetClass will panic if the number of ClassAttributes is set to anything other than one.

func GetClassDistribution 

func GetClassDistribution(inst FixedDataGrid) map[string]int

GetClassDistribution returns a map containing the count of each class type (indexed by the class' string representation).

func GetClassDistributionAfterSplit 

func GetClassDistributionAfterSplit(inst FixedDataGrid, at Attribute) map[string]map[string]int

GetClassDistributionAfterSplit returns the class distribution after a speculative split on a given Attribute.

func InstancesTrainTestSplit 

func InstancesTrainTestSplit(src FixedDataGrid, prop float64) (FixedDataGrid, FixedDataGrid)

InstancesTrainTestSplit takes a given Instances (src) and a train-test fraction (prop) and returns an array of two new Instances, one containing approximately that fraction and the other containing what's left.

IMPORTANT: this function is only meaningful when prop is between 0.0 and 1.0. Using any other values may result in odd behaviour.

func PackFloatToBytes 

func PackFloatToBytes(val float64) []byte

PackFloatToBytes returns a 8-byte slice containing the byte values of a float64.

func PackFloatToBytesInline 

func PackFloatToBytesInline(val float64, ret []byte)

PackFloatToBytesInline fills ret with the byte values of the float64 argument. ret must be at least 8 bytes in size.

func PackU64ToBytes 

func PackU64ToBytes(val uint64) []byte

PackU64ToBytes allocates a return value of appropriate length and fills it with the values of val.

func PackU64ToBytesInline 

func PackU64ToBytesInline(val uint64, ret []byte)

PackU64ToBytesInline fills ret with the byte values of val. Ret must have length at least 8.

func ParseCSV 

func ParseCSV(filepath string, label int, columns []int) (int, int, []string, []string, []float64)

ParseCSV parses a CSV file and returns the number of columns and rows, the headers, the labels associated with classification, and the data that will be used for training.

func ParseCSVBuildInstances 

func ParseCSVBuildInstances(filepath string, hasHeaders bool, u UpdatableDataGrid)

ParseCSVBuildInstances updates an [[#UpdatableDataGrid]] from a filepath in place

func ParseCSVGetRows 

func ParseCSVGetRows(filepath string) int

ParseCSVGetRows returns the number of rows in a given file.

func ParseCSVSniffAttributeNames 

func ParseCSVSniffAttributeNames(filepath string, hasHeaders bool) []string

ParseCSVSniffAttributeNames returns a slice containing the top row of a given CSV file, or placeholders if hasHeaders is false.

func SaveEstimatorToGob 

func SaveEstimatorToGob(path string, e *Estimator)

SaveEstimatorToGob serialises an estimator to a provided filepath, in gob format. See http://golang.org/pkg/encoding/gob for further details.

func SetClass 

func SetClass(at UpdatableDataGrid, row int, class string)

SetClass is a shortcut for updating the given class of a row.

IMPORTANT: SetClass will panic if the number of class Attributes is anything other than one.

func SetLogger 

func SetLogger(logger *log.Logger)

SetLogger sets the base logger for the entire golearn package.

func SetLoggerOut 

func SetLoggerOut(out io.Writer)

SetLoggerOut creates a new base logger for the entire golearn package using the given out instead of the default, os.Stdout. The other log options are set to the default, i.e. no prefix and no flags.

func Silent 

func Silent()

Silent turns off logging throughout the golearn package by setting the logger to write to dev/null.

func UnpackBytesToFloat 

func UnpackBytesToFloat(val []byte) float64

UnpackBytesToFloat converts a given byte slice into an equivalent float64.

func UnpackBytesToU64 

func UnpackBytesToU64(val []byte) uint64

UnpackBytesToU64 converst a given byte slice into a uint64 value.

Types

type Attribute 

type Attribute interface {
	// Returns the general characterstics of this Attribute .
	// to avoid the overhead of casting
	GetType() int
	// Returns the human-readable name of this Attribute.
	GetName() string
	// Sets the human-readable name of this Attribute.
	SetName(string)
	// Gets a human-readable overview of this Attribute for debugging.
	String() string
	// Converts a value given from a human-readable string into a system
	// representation. For example, a CategoricalAttribute with values
	// ["iris-setosa", "iris-virginica"] would return the float64
	// representation of 0 when given "iris-setosa".
	GetSysValFromString(string) []byte
	// Converts a given value from a system representation into a human
	// representation. For example, a CategoricalAttribute with values
	// ["iris-setosa", "iris-viriginica"] might return "iris-setosa"
	// when given 0.0 as the argument.
	GetStringFromSysVal([]byte) string
	// Tests for equality with another Attribute. Other Attributes are
	// considered equal if:
	// * They have the same type (i.e. FloatAttribute <> CategoricalAttribute)
	// * They have the same name
	// * If applicable, they have the same categorical values (though not
	//   necessarily in the same order).
	Equals(Attribute) bool
	// Tests whether two Attributes can be represented in the same pond
	// i.e. they're the same size, and their byte order makes them meaningful
	// when considered together
	Compatable(Attribute) bool
}

Attributes disambiguate columns of the feature matrix and declare their types.

func AttributeDifference 

func AttributeDifference(a1, a2 []Attribute) []Attribute

AttributeDifference returns the difference between two Attribute slices: i.e. all the values in a1 which do not occur in a2.

IMPORTANT: result is ordered the same as a1.

IMPORTANT: result only contains values from a1.

func AttributeDifferenceReferences 

func AttributeDifferenceReferences(a1, a2 []Attribute) []Attribute

AttributeDifferenceReferences returns the difference between two Attribute slices: i.e. all the values in a1 which do not occur in a2.

IMPORTANT: result is not guaranteed to be ordered.

IMPORTANT: done using pointers for speed, use AttributeDifference if the Attributes originate from different DataGrids.

func AttributeIntersect 

func AttributeIntersect(a1, a2 []Attribute) []Attribute

AttributeIntersect returns the intersection of two Attribute slices.

IMPORTANT: result is ordered in order of the first []Attribute argument.

IMPORTANT: result contains only Attributes from a1.

func AttributeIntersectReferences 

func AttributeIntersectReferences(a1, a2 []Attribute) []Attribute

AttributeIntersectReferences returns the intersection of two Attribute slices.

IMPORTANT: result is not guaranteed to be ordered.

IMPORTANT: done using pointers for speed, use AttributeDifference if the Attributes originate from different DataGrids.

func CheckCompatable 

func CheckCompatable(s1 FixedDataGrid, s2 FixedDataGrid) []Attribute

CheckCompatable checks whether two DataGrids have the same Attributes and if they do, it returns them.

func NonClassAttributes 

func NonClassAttributes(d DataGrid) []Attribute

NonClassAttrs returns all Attributes which aren't designated as a class Attribute.

func NonClassFloatAttributes 

func NonClassFloatAttributes(d DataGrid) []Attribute

NonClassFloatAttributes returns all FloatAttributes which aren't designated as a class Attribute.

func ParseCSVGetAttributes 

func ParseCSVGetAttributes(filepath string, hasHeaders bool) []Attribute

ParseCSVGetAttributes returns an ordered slice of appropriate-ly typed and named Attributes.

func ParseCSVSniffAttributeTypes 

func ParseCSVSniffAttributeTypes(filepath string, hasHeaders bool) []Attribute

ParseCSVSniffAttributeTypes returns a slice of appropriately-typed Attributes.

The type of a given attribute is determined by looking at the first data row of the CSV.

type AttributeGroup 

type AttributeGroup interface {

	// Adds a new Attribute
	AddAttribute(Attribute) error
	// Returns all Attributes
	Attributes() []Attribute

	// Gets the size of each row in bytes (rounded up)
	RowSize() int
	// Gets references to underlying memory
	Storage() []AttributeGroupStorageRef
	// Returns a human-readable summary
	String() string
	// contains filtered or unexported methods
}

AttributeGroups store related sequences of system values in memory for the DenseInstances structure.

type AttributeGroupStorageRef 

type AttributeGroupStorageRef struct {
	Storage []byte
	Rows    int
}

AttributeGroupStorageRef is a reference to a particular set of allocated rows within a FixedAttributeGroup

type AttributeSpec 

type AttributeSpec struct {
	// contains filtered or unexported fields
}

AttributeSpec is a pointer to a particular Attribute within a particular Instance structure and encodes position and storage information associated with that Attribute.

func ResolveAllAttributes 

func ResolveAllAttributes(d DataGrid) []AttributeSpec

ResolveAllAttributes returns every AttributeSpec

func ResolveAttributes 

func ResolveAttributes(d DataGrid, attrs []Attribute) []AttributeSpec

ResolveAttributes returns AttributeSpecs describing all of the Attributes.

func (*AttributeSpec) GetAttribute 

func (a *AttributeSpec) GetAttribute() Attribute

GetAttribute returns an AttributeSpec which matches a given Attribute.

func (*AttributeSpec) String 

func (a *AttributeSpec) String() string

String returns a human-readable description of this AttributeSpec.

type BaseClassifier 

type BaseClassifier struct {
	TrainingData *DataGrid
}

BaseClassifier stores options common to every classifier.

type BaseEstimator 

type BaseEstimator struct {
	Data *mat64.Dense
}

type BaseRegressor 

type BaseRegressor struct {
	Data   mat64.Dense
	Name   string
	Labels []float64
}

type BinaryAttribute 

type BinaryAttribute struct {
	Name string
}

BinaryAttributes can only represent 1 or 0.

func NewBinaryAttribute 

func NewBinaryAttribute(name string) *BinaryAttribute

NewBinaryAttribute creates a BinaryAttribute with the given name

func (*BinaryAttribute) Compatable 

func (b *BinaryAttribute) Compatable(other Attribute) bool

Compatable checks whether this Attribute can be represented in the same pond as another.

func (*BinaryAttribute) Equals 

func (b *BinaryAttribute) Equals(other Attribute) bool

Equals checks for equality with another BinaryAttribute.

func (*BinaryAttribute) GetName 

func (b *BinaryAttribute) GetName() string

GetName returns the name of this Attribute.

func (*BinaryAttribute) GetStringFromSysVal 

func (b *BinaryAttribute) GetStringFromSysVal(val []byte) string

GetStringFromSysVal returns either 1 or 0.

func (*BinaryAttribute) GetSysValFromString 

func (b *BinaryAttribute) GetSysValFromString(userVal string) []byte

GetSysValFromString returns either 1 or 0 in a single byte.

func (*BinaryAttribute) GetType 

func (b *BinaryAttribute) GetType() int

GetType returns BinaryType.

func (*BinaryAttribute) SetName 

func (b *BinaryAttribute) SetName(name string)

SetName sets the name of this Attribute.

func (*BinaryAttribute) String 

func (b *BinaryAttribute) String() string

String returns a human-redable representation.

type BinaryAttributeGroup 

type BinaryAttributeGroup struct {
	FixedAttributeGroup
}

BinaryAttributeGroups contain only BinaryAttributes Compact each Attribute to a bit for better storage

func (*BinaryAttributeGroup) RowSize 

func (b *BinaryAttributeGroup) RowSize() int

func (*BinaryAttributeGroup) String 

func (b *BinaryAttributeGroup) String() string

String gets a human-readable view of this group

type CategoricalAttribute 

type CategoricalAttribute struct {
	Name string
	// contains filtered or unexported fields
}

CategoricalAttribute is an Attribute implementation which stores discrete string values - useful for representing classes.

func NewCategoricalAttribute 

func NewCategoricalAttribute() *CategoricalAttribute

NewCategoricalAttribute creates a blank CategoricalAttribute.

func (*CategoricalAttribute) Compatable 

func (Attr *CategoricalAttribute) Compatable(other Attribute) bool

Compatable checks that this CategoricalAttribute has the same values as another, in the same order.

func (*CategoricalAttribute) Equals 

func (Attr *CategoricalAttribute) Equals(other Attribute) bool

Equals checks equality against another Attribute.

Two CategoricalAttributes are considered equal if they contain the same values and have the same name. Otherwise, this function returns false.

func (*CategoricalAttribute) GetName 

func (Attr *CategoricalAttribute) GetName() string

GetName returns the human-readable name assigned to this attribute.

func (*CategoricalAttribute) GetStringFromSysVal 

func (Attr *CategoricalAttribute) GetStringFromSysVal(rawVal []byte) string

GetStringFromSysVal returns a human-readable value from the given system-representation value val.

IMPORTANT: This function calls panic() if the value is greater than the length of the array. TODO: Return a user-configurable default instead.

func (*CategoricalAttribute) GetSysVal 

func (Attr *CategoricalAttribute) GetSysVal(userVal string) []byte

GetSysVal returns the system representation of userVal as an index into the Values slice If the userVal can't be found, it returns nothing.

func (*CategoricalAttribute) GetSysValFromString 

func (Attr *CategoricalAttribute) GetSysValFromString(rawVal string) []byte

GetSysValFromString returns the system representation of rawVal as an index into the Values slice. If rawVal is not inside the Values slice, it is appended.

IMPORTANT: If no system representation yet exists, this functions adds it. If you need to determine whether rawVal exists: use GetSysVal and check for a zero-length return value.

Example: if the CategoricalAttribute contains the values ["iris-setosa", "iris-virginica"] and "iris-versicolor" is provided as the argument, the Values slide becomes ["iris-setosa", "iris-virginica", "iris-versicolor"] and 2.00 is returned as the system representation.

func (*CategoricalAttribute) GetType 

func (Attr *CategoricalAttribute) GetType() int

GetType returns CategoricalType to avoid casting overhead.

func (*CategoricalAttribute) GetUsrVal 

func (Attr *CategoricalAttribute) GetUsrVal(sysVal []byte) string

GetUsrVal returns a human-readable representation of the given sysVal.

IMPORTANT: this function doesn't check the boundaries of the array.

func (*CategoricalAttribute) GetValues 

func (Attr *CategoricalAttribute) GetValues() []string

GetValues returns all the values currently defined

func (*CategoricalAttribute) SetName 

func (Attr *CategoricalAttribute) SetName(name string)

SetName sets the human-readable name on this attribute.

func (*CategoricalAttribute) String 

func (Attr *CategoricalAttribute) String() string

String returns a human-readable summary of this Attribute.

Returns a string containing the list of human-readable values this CategoricalAttribute can take.

type Classifier 

type Classifier interface {
	// Takes a set of Instances, copies the class Attribute
	// and constructs a new set of Instances of equivalent
	// length with only the class Attribute and fills it in
	// with predictions.
	Predict(FixedDataGrid) FixedDataGrid
	// Takes a set of instances and updates the Classifier's
	// internal structures to enable prediction
	Fit(FixedDataGrid)
	// Why not make every classifier return a nice-looking string?
	String() string
}

Classifier implementations predict categorical class labels.

type DataGrid 

type DataGrid interface {
	// Retrieves a given Attribute's specification
	GetAttribute(Attribute) (AttributeSpec, error)
	// Retrieves details of every Attribute
	AllAttributes() []Attribute
	// Marks an Attribute as a class Attribute
	AddClassAttribute(Attribute) error
	// Unmarks an Attribute as a class Attribute
	RemoveClassAttribute(Attribute) error
	// Returns details of all class Attributes
	AllClassAttributes() []Attribute
	// Gets the bytes at a given position or nil
	Get(AttributeSpec, int) []byte
	// Convenience function for iteration.
	MapOverRows([]AttributeSpec, func([][]byte, int) (bool, error)) error
}

DataGrid implementations represent data addressable by rows and columns.

type DenseInstances 

type DenseInstances struct {
	// contains filtered or unexported fields
}

DenseInstances stores each Attribute value explicitly in a large grid.

func NewDenseInstances 

func NewDenseInstances() *DenseInstances

NewDenseInstances generates a new DenseInstances set with an anonymous EDF mapping and default settings.

func ParseCSVToInstances 

func ParseCSVToInstances(filepath string, hasHeaders bool) (instances *DenseInstances, err error)

ParseCSVToInstances reads the CSV file given by filepath and returns the read Instances.

func (*DenseInstances) AddAttribute 

func (inst *DenseInstances) AddAttribute(a Attribute) AttributeSpec

AddAttribute adds an Attribute to this set of DenseInstances Creates a default AttributeGroup for it if a suitable one doesn't exist. Returns an AttributeSpec for subsequent Set() calls.

IMPORTANT: will panic if storage has been allocated via Extend.

func (*DenseInstances) AddAttributeToAttributeGroup 

func (inst *DenseInstances) AddAttributeToAttributeGroup(newAttribute Attribute, ag string) (AttributeSpec, error)

AddAttributeToAttributeGroup adds an Attribute to a given ag

func (*DenseInstances) AddClassAttribute 

func (inst *DenseInstances) AddClassAttribute(a Attribute) error

AddClassAttribute sets an Attribute to be a class Attribute.

func (*DenseInstances) AllAttributes 

func (inst *DenseInstances) AllAttributes() []Attribute

AllAttributes returns a slice of all Attributes.

func (*DenseInstances) AllClassAttributes 

func (inst *DenseInstances) AllClassAttributes() []Attribute

AllClassAttributes returns a slice of Attributes which have been designated class Attributes.

func (*DenseInstances) CreateAttributeGroup 

func (inst *DenseInstances) CreateAttributeGroup(name string, size int) (err error)

CreateAttributeGroup adds a new AttributeGroup to this set of instances with a given name. If the size is 0, a bit-ag is added if the size of not 0, then the size of each ag attribute is set to that number of bytes.

func (*DenseInstances) Equal 

func (inst *DenseInstances) Equal(other DataGrid) bool

Equal checks whether a given Instance set is exactly the same as another: same size and same values (as determined by the Attributes)

IMPORTANT: does not explicitly check if the Attributes are considered equal.

func (*DenseInstances) Extend 

func (inst *DenseInstances) Extend(rows int) error

Extend extends this set of Instances to store rows additional rows. It's recommended to set rows to something quite large.

IMPORTANT: panics if the allocation fails

func (*DenseInstances) Get 

func (inst *DenseInstances) Get(a AttributeSpec, row int) []byte

Get gets a particular Attribute (given as an AttributeSpec) on a particular row. AttributeSpecs can be obtained using GetAttribute() or AddAttribute()

func (*DenseInstances) GetAttribute 

func (inst *DenseInstances) GetAttribute(get Attribute) (AttributeSpec, error)

GetAttribute returns an Attribute equal to the argument.

TODO: Write a function to pre-compute this once we've allocated TODO: Write a utility function which retrieves all AttributeSpecs for a given instance set.

func (*DenseInstances) GetAttributeGroup 

func (inst *DenseInstances) GetAttributeGroup(name string) (AttributeGroup, error)

GetAttributeGroup returns a reference to a AttributeGroup of a given name /

func (*DenseInstances) MapOverRows 

func (inst *DenseInstances) MapOverRows(asv []AttributeSpec, mapFunc func([][]byte, int) (bool, error)) error

MapOverRows passes each row map into a function. First argument is a list of AttributeSpec in the order they're needed in for the function. The second is the function to call on each row.

func (*DenseInstances) RemoveClassAttribute 

func (inst *DenseInstances) RemoveClassAttribute(a Attribute) error

RemoveClassAttribute removes an Attribute from the set of class Attributes.

func (*DenseInstances) RowString 

func (inst *DenseInstances) RowString(row int) string

RowString returns a string representation of a given row.

func (*DenseInstances) Set 

func (inst *DenseInstances) Set(a AttributeSpec, row int, val []byte)

Set sets a particular Attribute (given as an AttributeSpec) on a particular row to a particular value.

AttributeSpecs can be obtained using GetAttribute() or AddAttribute().

IMPORTANT: Will panic() if the AttributeSpec isn't valid

IMPORTANT: Will panic() if the row is too large

IMPORTANT: Will panic() if the val is not the right length

func (*DenseInstances) Size 

func (inst *DenseInstances) Size() (int, int)

Size returns the number of Attributes as the first return value and the maximum allocated row as the second value.

func (*DenseInstances) String 

func (inst *DenseInstances) String() string

String returns a human-readable summary of this dataset.

type Estimator 

type Estimator interface {
	Fit()
}

An Estimator is object that can ingest some data and train on it.

type Filter 

type Filter interface {
	// Adds an Attribute to the filter
	AddAttribute(Attribute) error
	// Allows mapping old to new Attributes
	GetAttributesAfterFiltering() []FilteredAttribute
	// Gets a string for printing
	String() string
	// Accepts an old Attribute, the new one and returns a sequence
	Transform(Attribute, Attribute, []byte) []byte
	// Builds the filter
	Train() error
}

Filters transform the byte sequences stored in DataGrid implementations.

type FilteredAttribute 

type FilteredAttribute struct {
	Old Attribute
	New Attribute
}

FilteredAttributes represent a mapping from the output generated by a filter to the original value.

type FixedAttributeGroup 

type FixedAttributeGroup struct {
	// contains filtered or unexported fields
}

FixedAttributeGroups contain a particular number of rows of a particular number of Attributes, all of a given type.

func (*FixedAttributeGroup) AddAttribute 

func (f *FixedAttributeGroup) AddAttribute(a Attribute) error

AddAttribute adds an attribute to this FixedAttributeGroup

func (*FixedAttributeGroup) Attributes 

func (f *FixedAttributeGroup) Attributes() []Attribute

Attributes returns a slice of Attributes in this FixedAttributeGroup

func (*FixedAttributeGroup) RowSize 

func (f *FixedAttributeGroup) RowSize() int

RowSize returns the size of each row in bytes

func (*FixedAttributeGroup) Storage 

func (f *FixedAttributeGroup) Storage() []AttributeGroupStorageRef

Storage returns a slice of FixedAttributeGroupStorageRefs which can be used to access the memory in this pond.

func (*FixedAttributeGroup) String 

func (f *FixedAttributeGroup) String() string

type FixedDataGrid 

type FixedDataGrid interface {
	DataGrid
	// Returns a string representation of a given row
	RowString(int) string
	// Returns the number of Attributes and rows currently allocated
	Size() (int, int)
}

FixedDataGrid implementations have a size known in advance and implement all of the functionality offered by DataGrid implementations.

func LazyShuffle 

func LazyShuffle(from FixedDataGrid) FixedDataGrid

LazyShuffle randomizes the row order without re-ordering the rows via an InstancesView.

func LazySort 

func LazySort(inst FixedDataGrid, direction SortDirection, attrs []AttributeSpec) (FixedDataGrid, error)

LazySort also does a sort, but returns an InstanceView and doesn't actually reorder the rows, just makes it look like they've been reordered See also: Sort

func SampleWithReplacement 

func SampleWithReplacement(from FixedDataGrid, size int) FixedDataGrid

SampleWithReplacement returns a new FixedDataGrid containing an equal number of random rows drawn from the original FixedDataGrid

IMPORTANT: There's a high chance of seeing duplicate rows whenever size is close to the row count.

func Shuffle 

func Shuffle(from FixedDataGrid) FixedDataGrid

Shuffle randomizes the row order either in place (if DenseInstances) or using LazyShuffle.

func Sort 

func Sort(inst FixedDataGrid, direction SortDirection, attrs []AttributeSpec) (FixedDataGrid, error)

Sort does a radix sort of DenseInstances, using SortDirection direction (Ascending or Descending) with attrs as a slice of Attribute indices that you want to sort by.

IMPORTANT: Radix sort is not stable, so ordering outside the attributes used for sorting is arbitrary.

type FloatAttribute 

type FloatAttribute struct {
	Name      string
	Precision int
}

FloatAttribute is an implementation which stores floating point representations of numbers.

func NewFloatAttribute 

func NewFloatAttribute(name string) *FloatAttribute

NewFloatAttribute returns a new FloatAttribute with a default precision of 2 decimal places

func (*FloatAttribute) CheckSysValFromString 

func (Attr *FloatAttribute) CheckSysValFromString(rawVal string) ([]byte, error)

CheckSysValFromString confirms whether a given rawVal can be converted into a valid system representation. If it can't, the returned value is nil.

func (*FloatAttribute) Compatable 

func (Attr *FloatAttribute) Compatable(other Attribute) bool

Compatable checks whether this FloatAttribute can be ponded with another Attribute (checks if they're both FloatAttributes)

func (*FloatAttribute) Equals 

func (Attr *FloatAttribute) Equals(other Attribute) bool

Equals tests a FloatAttribute for equality with another Attribute.

Returns false if the other Attribute has a different name or if the other Attribute is not a FloatAttribute.

func (*FloatAttribute) GetFloatFromSysVal 

func (Attr *FloatAttribute) GetFloatFromSysVal(rawVal []byte) float64

GetFloatFromSysVal converts a given system value to a float

func (*FloatAttribute) GetName 

func (Attr *FloatAttribute) GetName() string

GetName returns this FloatAttribute's human-readable name.

func (*FloatAttribute) GetStringFromSysVal 

func (Attr *FloatAttribute) GetStringFromSysVal(rawVal []byte) string

GetStringFromSysVal converts a given system value to to a string with two decimal places of precision.

func (*FloatAttribute) GetSysValFromString 

func (Attr *FloatAttribute) GetSysValFromString(rawVal string) []byte

GetSysValFromString parses the given rawVal string to a float64 and returns it.

float64 happens to be a 1-to-1 mapping to the system representation. IMPORTANT: This function panic()s if rawVal is not a valid float. Use CheckSysValFromString to confirm.

func (*FloatAttribute) GetType 

func (Attr *FloatAttribute) GetType() int

GetType returns Float64Type.

func (*FloatAttribute) SetName 

func (Attr *FloatAttribute) SetName(name string)

SetName sets this FloatAttribute's human-readable name.

func (*FloatAttribute) String 

func (Attr *FloatAttribute) String() string

String returns a human-readable summary of this Attribute. e.g. "FloatAttribute(Sepal Width)"

type InstancesView 

type InstancesView struct {
	// contains filtered or unexported fields
}

InstancesViews hide or re-order Attributes and rows from a given DataGrid to make it appear that they've been deleted.

func NewInstancesViewFromAttrs 

func NewInstancesViewFromAttrs(src FixedDataGrid, attrs []Attribute) *InstancesView

NewInstancesViewFromAttrs creates a new InstancesView from a source FixedDataGrid and a slice of Attributes.

Only the Attributes specified will appear in this InstancesView.

func NewInstancesViewFromRows 

func NewInstancesViewFromRows(src FixedDataGrid, rows map[int]int) *InstancesView

NewInstancesViewFromRows creates a new InstancesView from a source FixedDataGrid and row -> row mapping. The key of the rows map is the row as it exists within this mapping: for example an entry like 5 -> 1 means that row 1 in src will appear at row 5 in the Instancesview.

Rows are not masked in this implementation, meaning that all rows which are left unspecified appear as normal.

func NewInstancesViewFromVisible 

func NewInstancesViewFromVisible(src FixedDataGrid, rows []int, attrs []Attribute) *InstancesView

NewInstancesViewFromVisible creates a new InstancesView from a source FixedDataGrid, a slice of row numbers and a slice of Attributes.

Only the rows specified will appear in this InstancesView, and they will appear in the same order they appear within the rows array.

Only the Attributes specified will appear in this InstancesView. Retrieving Attribute specifications from this InstancesView will maintain their order.

func (*InstancesView) AddClassAttribute 

func (v *InstancesView) AddClassAttribute(a Attribute) error

AddClassAttribute adds the given Attribute to the set of defined class Attributes, if it hasn't been filtered.

func (*InstancesView) AllAttributes 

func (v *InstancesView) AllAttributes() []Attribute

AllAttributes returns every Attribute which hasn't been filtered.

func (*InstancesView) AllClassAttributes 

func (v *InstancesView) AllClassAttributes() []Attribute

AllClassAttributes returns all the Attributes currently defined as being class Attributes.

func (*InstancesView) Get 

func (v *InstancesView) Get(as AttributeSpec, row int) []byte

Get returns a sequence of bytes stored under a given Attribute on a given row.

IMPORTANT: The AttributeSpec is unverified, meaning it's possible to return values from Attributes filtered by this InstancesView if the underlying AttributeSpec is known.

func (*InstancesView) GetAttribute 

func (v *InstancesView) GetAttribute(a Attribute) (AttributeSpec, error)

GetAttribute returns an Attribute specification matching an Attribute if it has not been filtered.

The AttributeSpecs returned are the same as those returned by the source FixedDataGrid.

func (*InstancesView) MapOverRows 

func (v *InstancesView) MapOverRows(as []AttributeSpec, rowFunc func([][]byte, int) (bool, error)) error

MapOverRows, see DenseInstances.MapOverRows.

IMPORTANT: MapOverRows is not guaranteed to be ordered, but this one especially so.

func (*InstancesView) RemoveClassAttribute 

func (v *InstancesView) RemoveClassAttribute(a Attribute) error

RemoveClassAttribute removes the given Attribute from the set of class Attributes.

func (*InstancesView) RowString 

func (v *InstancesView) RowString(row int) string

RowString returns a string representation of a given row.

func (*InstancesView) Size 

func (v *InstancesView) Size() (int, int)

Size Returns the number of Attributes and rows this InstancesView contains.

func (*InstancesView) String 

func (v *InstancesView) String() string

String returns a human-readable summary of this InstancesView.

type LazilyFilteredInstances 

type LazilyFilteredInstances struct {
	// contains filtered or unexported fields
}

LazilyFilteredInstances map a Filter over an underlying FixedDataGrid and are a memory-efficient way of applying them.

func NewLazilyFilteredInstances 

func NewLazilyFilteredInstances(src FixedDataGrid, f Filter) *LazilyFilteredInstances

NewLazilyFitleredInstances returns a new FixedDataGrid after applying the given Filter to the Attributes it includes. Unfiltered Attributes are passed through without modification.

func (*LazilyFilteredInstances) AddClassAttribute 

func (l *LazilyFilteredInstances) AddClassAttribute(cls Attribute) error

AddClassAttribute adds a given Attribute (either before or after filtering) to the set of defined class Attributes.

func (*LazilyFilteredInstances) AllAttributes 

func (l *LazilyFilteredInstances) AllAttributes() []Attribute

AllAttributes returns every Attribute defined in the source datagrid, in addition to the revised Attributes created by the filter.

func (*LazilyFilteredInstances) AllClassAttributes 

func (l *LazilyFilteredInstances) AllClassAttributes() []Attribute

AllClassAttributes returns details of all Attributes currently specified as being class Attributes.

If applicable, the Attributes returned are those after modification by the Filter.

func (*LazilyFilteredInstances) Get 

func (l *LazilyFilteredInstances) Get(as AttributeSpec, row int) []byte

Get returns a transformed byte slice stored at a given AttributeSpec and row.

func (*LazilyFilteredInstances) GetAttribute 

func (l *LazilyFilteredInstances) GetAttribute(target Attribute) (AttributeSpec, error)

GetAttribute returns an AttributeSpecification for a given Attribute

func (*LazilyFilteredInstances) MapOverRows 

func (l *LazilyFilteredInstances) MapOverRows(asv []AttributeSpec, mapFunc func([][]byte, int) (bool, error)) error

MapOverRows maps an iteration mapFunc over the bytes contained in the source FixedDataGrid, after modification by the filter.

func (*LazilyFilteredInstances) RemoveClassAttribute 

func (l *LazilyFilteredInstances) RemoveClassAttribute(cls Attribute) error

RemoveClassAttribute removes a given Attribute (either before or after filtering) from the set of defined class Attributes.

func (*LazilyFilteredInstances) RowString 

func (l *LazilyFilteredInstances) RowString(row int) string

RowString returns a string representation of a given row after filtering.

func (*LazilyFilteredInstances) Size 

func (l *LazilyFilteredInstances) Size() (int, int)

Size returns the number of Attributes and rows of the underlying FixedDataGrid.

func (*LazilyFilteredInstances) String 

func (l *LazilyFilteredInstances) String() string

String returns a human-readable summary of this FixedDataGrid after filtering.

type Model 

type Model interface {
	Score()
}

A Model is a supervised learning object, that is possible of scoring accuracy against a test set.

type Predictor 

type Predictor interface {
	Predict()
}

A Predictor is an object that provides predictions.

type SortDirection 

type SortDirection int

SortDirection specifies sorting direction... 

const (
	// Descending says that Instances should be sorted high to low...
	Descending SortDirection = 1
	// Ascending states that Instances should be sorted low to high...
	Ascending SortDirection = 2
)

type UpdatableDataGrid 

type UpdatableDataGrid interface {
	FixedDataGrid
	// Sets a given Attribute and row to a byte sequence.
	Set(AttributeSpec, int, []byte)
	// Adds an Attribute to the grid.
	AddAttribute(Attribute) AttributeSpec
	// Allocates additional room to hold a number of rows
	Extend(int) error
}

UpdatableDataGrid implementations can be changed in addition to implementing all of the functionality offered by FixedDataGrid implementations.

func GeneratePredictionVector 

func GeneratePredictionVector(from FixedDataGrid) UpdatableDataGrid

GeneratePredictionVector selects the class Attributes from a given FixedDataGrid and returns something which can hold the predictions.

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