README
¶
utils
Package utils provides shared utilities for datascience including combinatorics, convergence checking, state name helpers, and validation functions.
Import path: github.com/asymmetric-effort/datascience/lib/pgm/utils
Combinatorics
| Function | Description |
|---|---|
Combinations(items, k) |
Generate all k-element combinations of items |
Permutations(items) |
Generate all permutations using Heap's algorithm |
import "github.com/asymmetric-effort/datascience/lib/pgm/utils"
combos := utils.Combinations([]string{"A", "B", "C"}, 2)
// [["A","B"], ["A","C"], ["B","C"]]
perms := utils.Permutations([]string{"A", "B"})
// [["A","B"], ["B","A"]]
Convergence Checking
| Type/Function | Description |
|---|---|
ConvergenceChecker |
Tracks a scalar across iterations, reports convergence when change < tolerance |
NewConvergenceChecker(tolerance, maxIter) |
Create a checker with given tolerance and max iterations |
cc := utils.NewConvergenceChecker(1e-6, 1000)
for {
value := computeObjective()
if cc.Update(value) {
break // converged or max iterations reached
}
}
fmt.Println(cc.Converged()) // true if change < tolerance
fmt.Println(cc.Iteration()) // number of iterations run
State Name Helpers
| Function | Description |
|---|---|
GenerateStateNames(cardinality) |
Produce default names: ["s0", "s1", ..., "s{n-1}"] |
ValidateStateNames(names, cardinality) |
Check length matches and no duplicates |
StateIndex(names, name) |
Find the index of a state name |
names := utils.GenerateStateNames(3) // ["s0", "s1", "s2"]
err := utils.ValidateStateNames(names, 3) // nil
idx, err := utils.StateIndex(names, "s1") // 1, nil
Validation Helpers
| Function | Description |
|---|---|
ValidatePositiveInt(name, value) |
Error if value <= 0 |
ValidateNonNegativeFloat(name, value) |
Error if value < 0 |
ValidateProbability(name, value) |
Error if value not in [0, 1] |
ValidateProbabilityDistribution(name, values, tolerance) |
Error if values don't sum to 1 |
err := utils.ValidatePositiveInt("nSamples", 100) // nil
err = utils.ValidateProbability("p", 1.5) // error
probs := []float64{0.3, 0.3, 0.4}
err = utils.ValidateProbabilityDistribution("prior", probs, 1e-9) // nil
Documentation
¶
Overview ¶
Package utils provides shared utilities for datascience including parsing, optimization helpers, and compatibility functions.
Index ¶
- func CartesianProduct(sets [][]int) [][]int
- func Combinations(items []string, k int) [][]string
- func GenerateStateNames(cardinality int) []string
- func Permutations(items []string) [][]string
- func SafePath(path string) (string, error)
- func StateIndex(names []string, name string) (int, error)
- func StateNameMap(variables []string, stateNames map[string][]string) map[string]map[string]int
- func ValidateNoInf(name string, values []float64) error
- func ValidateNoNaN(name string, values []float64) error
- func ValidateNonNegativeFloat(name string, value float64) error
- func ValidatePositiveInt(name string, value int) error
- func ValidateProbability(name string, value float64) error
- func ValidateProbabilityDistribution(name string, values []float64, tolerance float64) error
- func ValidateStateNames(names []string, cardinality int) error
- type ConvergenceChecker
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func CartesianProduct ¶
CartesianProduct computes the Cartesian product of integer sets. For example, CartesianProduct([][]int{{0,1},{2,3}}) returns [[0,2],[0,3],[1,2],[1,3]].
func Combinations ¶
Combinations generates all k-element combinations of items. The order of elements within each combination matches their order in items.
func GenerateStateNames ¶
GenerateStateNames produces default state names ["s0", "s1", ..., "s{n-1}"].
func Permutations ¶
Permutations generates all permutations of items using Heap's algorithm.
func SafePath ¶ added in v0.1.1
SafePath validates that a file path does not contain directory traversal sequences or other dangerous patterns.
func StateIndex ¶
StateIndex returns the index of name within names, or an error if not found.
func StateNameMap ¶
StateNameMap builds a mapping from variable name to state name to index. variables lists the variable names; stateNames maps each variable to its ordered slice of state names.
func ValidateNoInf ¶
ValidateNoInf returns an error if any value is infinite.
func ValidateNoNaN ¶
ValidateNoNaN returns an error if any value is NaN.
func ValidateNonNegativeFloat ¶
ValidateNonNegativeFloat returns an error if value is negative.
func ValidatePositiveInt ¶
ValidatePositiveInt returns an error if value is not strictly positive.
func ValidateProbability ¶
ValidateProbability returns an error if value is not in [0, 1].
func ValidateProbabilityDistribution ¶
ValidateProbabilityDistribution returns an error if the values do not sum to 1 within the given tolerance.
func ValidateStateNames ¶
ValidateStateNames checks that names has the expected length and contains no duplicates.
Types ¶
type ConvergenceChecker ¶
type ConvergenceChecker struct {
// contains filtered or unexported fields
}
ConvergenceChecker tracks a scalar value across iterations and determines whether it has converged (i.e., the absolute change falls below a tolerance).
func NewConvergenceChecker ¶
func NewConvergenceChecker(tolerance float64, maxIter int) *ConvergenceChecker
NewConvergenceChecker creates a ConvergenceChecker with the given tolerance and maximum iteration count.
func (*ConvergenceChecker) Converged ¶
func (c *ConvergenceChecker) Converged() bool
Converged returns whether convergence has been detected.
func (*ConvergenceChecker) Iterations ¶
func (c *ConvergenceChecker) Iterations() int
Iterations returns the number of Update calls so far.
func (*ConvergenceChecker) Reset ¶
func (c *ConvergenceChecker) Reset()
Reset clears the checker state so it can be reused.
func (*ConvergenceChecker) Update ¶
func (c *ConvergenceChecker) Update(value float64) bool
Update records a new value and returns true if the checker has converged (the absolute change from the previous value is less than tolerance) or the maximum number of iterations has been reached.
Source Files