f64s

Documentation

Overview

Package f64s provides common operations on float64 slices.

Index

• func Filter(dst, src []float64, f func(v float64) bool) []float64
• func Find(dst []int, src []float64, f func(v float64) bool) []int
• func Map(dst, src []float64, f func(v float64) float64) []float64
• func Take(dst, src []float64, indices []int) []float64

Examples

• Filter
• Find
• Map
• Take

Functions

func Filter

func Filter(dst, src []float64, f func(v float64) bool) []float64

Filter creates a slice with all the elements x_i of src for which f(x_i) is true. Filter uses dst as work buffer, storing elements at the start of the slice. Filter clears dst if a slice is passed, and allocates a new slice if dst is nil.

Example

An example of slice filtering

package main

import (
	"fmt"

	"go-hep.org/x/hep/sliceop/f64s"
)

func main() {
	slice := []float64{1, 2, -99, 4, 5, -99, 7}
	condition := func(x float64) bool { return x > 0 }
	fmt.Println(f64s.Filter(nil, slice, condition))

}

Output:

[1 2 4 5 7]

func Find

func Find(dst []int, src []float64, f func(v float64) bool) []int

Find creates a slice with all indices corresponding to elements for which f(x) is true. Find uses dst as work buffer, storing indices at the start of the slice. Find clears dst if a slice is passed, and allocates a new slice if dst is nil.

Example

An example of slice finding

package main

import (
	"fmt"

	"go-hep.org/x/hep/sliceop/f64s"
)

func main() {
	slice := []float64{1, 2, -99, 4, 5, -99, 7}
	condition := func(x float64) bool { return x == -99 }
	fmt.Println(f64s.Find(nil, slice, condition))

}

Output:

[2 5]

func Map

func Map(dst, src []float64, f func(v float64) float64) []float64

Map creates a slice with all the elements f(x_i) where x_i are elements from src. Map uses dst as work buffer, storing elements at the start of the slice. Map allocates a new slice if dst is nil. Map will panic if the lengths of src and dst differ.

Example

An example of slice mapping

package main

import (
	"fmt"

	"go-hep.org/x/hep/sliceop/f64s"
)

func main() {
	slice := []float64{1, 2, -99, 4, 5, -99, 7}
	operation := func(x float64) float64 { return x * x }
	fmt.Println(f64s.Map(nil, slice, operation))

}

Output:

[1 4 9801 16 25 9801 49]

func Take

func Take(dst, src []float64, indices []int) []float64

Take creates a sub-slice of src with all elements indiced by the provided indices. Take uses dst as work buffer, storing elements at the start of the slice. Take clears dst if a slice is passed, and allocates a new slice if dst is nil. Take will panic if indices is not sorted or has duplicates. Take will panic if length of indices is larger than length of src. Take will panic if length of indices is different from length of dst.

Example

An example of taking a sub-slice defined by indices

package main

import (
	"fmt"

	"go-hep.org/x/hep/sliceop/f64s"
)

func main() {
	slice := []float64{1, 2, -99, 4, 5, -99, 7}
	indices := []int{2, 5}
	fmt.Println(f64s.Take(nil, slice, indices))

}

Output:

[-99 -99]