lo/docs/data/simd-meanby.md

name, slug, sourceRef, category, subCategory, similarHelpers, position, signatures

name	slug	sourceRef	category	subCategory	similarHelpers	position	signatures
MeanBy	meanby	exp/simd/math.go#L1006	exp	simd	exp#simd#mean exp#simd#sumby	30	func MeanByInt8[T any, R ~int8](collection []T, iteratee func(item T) R) R func MeanByInt16[T any, R ~int16](collection []T, iteratee func(item T) R) R func MeanByInt32[T any, R ~int32](collection []T, iteratee func(item T) R) R func MeanByInt64[T any, R ~int64](collection []T, iteratee func(item T) R) R func MeanByUint8[T any, R ~uint8](collection []T, iteratee func(item T) R) R func MeanByUint16[T any, R ~uint16](collection []T, iteratee func(item T) R) R func MeanByUint32[T any, R ~uint32](collection []T, iteratee func(item T) R) R func MeanByUint64[T any, R ~uint64](collection []T, iteratee func(item T) R) R func MeanByFloat32[T any, R ~float32](collection []T, iteratee func(item T) R) R func MeanByFloat64[T any, R ~float64](collection []T, iteratee func(item T) R) R func MeanByInt8x16[T any, R ~int8](collection []T, iteratee func(item T) R) R func MeanByInt8x32[T any, R ~int8](collection []T, iteratee func(item T) R) R func MeanByInt8x64[T any, R ~int8](collection []T, iteratee func(item T) R) R func MeanByInt16x8[T any, R ~int16](collection []T, iteratee func(item T) R) R func MeanByInt16x16[T any, R ~int16](collection []T, iteratee func(item T) R) R func MeanByInt16x32[T any, R ~int16](collection []T, iteratee func(item T) R) R func MeanByInt32x4[T any, R ~int32](collection []T, iteratee func(item T) R) R func MeanByInt32x8[T any, R ~int32](collection []T, iteratee func(item T) R) R func MeanByInt32x16[T any, R ~int32](collection []T, iteratee func(item T) R) R func MeanByInt64x2[T any, R ~int64](collection []T, iteratee func(item T) R) R func MeanByInt64x4[T any, R ~int64](collection []T, iteratee func(item T) R) R func MeanByInt64x8[T any, R ~int64](collection []T, iteratee func(item T) R) R func MeanByUint8x16[T any, R ~uint8](collection []T, iteratee func(item T) R) R func MeanByUint8x32[T any, R ~uint8](collection []T, iteratee func(item T) R) R func MeanByUint8x64[T any, R ~uint8](collection []T, iteratee func(item T) R) R func MeanByUint16x8[T any, R ~uint16](collection []T, iteratee func(item T) R) R func MeanByUint16x16[T any, R ~uint16](collection []T, iteratee func(item T) R) R func MeanByUint16x32[T any, R ~uint16](collection []T, iteratee func(item T) R) R func MeanByUint32x4[T any, R ~uint32](collection []T, iteratee func(item T) R) R func MeanByUint32x8[T any, R ~uint32](collection []T, iteratee func(item T) R) R func MeanByUint32x16[T any, R ~uint32](collection []T, iteratee func(item T) R) R func MeanByUint64x2[T any, R ~uint64](collection []T, iteratee func(item T) R) R func MeanByUint64x4[T any, R ~uint64](collection []T, iteratee func(item T) R) R func MeanByUint64x8[T any, R ~uint64](collection []T, iteratee func(item T) R) R func MeanByFloat32x4[T any, R ~float32](collection []T, iteratee func(item T) R) R func MeanByFloat32x8[T any, R ~float32](collection []T, iteratee func(item T) R) R func MeanByFloat32x16[T any, R ~float32](collection []T, iteratee func(item T) R) R func MeanByFloat64x2[T any, R ~float64](collection []T, iteratee func(item T) R) R func MeanByFloat64x4[T any, R ~float64](collection []T, iteratee func(item T) R) R func MeanByFloat64x8[T any, R ~float64](collection []T, iteratee func(item T) R) R

MeanBy transforms a collection using an iteratee function and calculates the arithmetic mean of the result using SIMD instructions. The automatic dispatch functions (e.g., MeanByInt8) will select the best SIMD variant based on CPU capabilities. The specific variants (e.g., MeanByInt8x32) use a fixed SIMD instruction set regardless of CPU capabilities.

Note

: The automatic dispatch functions (e.g., MeanByInt8) will use the best available SIMD variant for the current CPU. Use specific variants (e.g., MeanByInt8x32) only if you know your target CPU supports that instruction set.

type Person struct {
    Name string
    Age  int8
}

people := []Person{
    {Name: "Alice", Age: 20},
    {Name: "Bob", Age: 30},
    {Name: "Charlie", Age: 40},
}

// Automatic dispatch - uses best available SIMD
mean := simd.MeanByInt8(people, func(p Person) int8 {
    return p.Age
})
// 30

type Product struct {
    Name  string
    Price float32
}

products := []Product{
    {Name: "Widget", Price: 10.50},
    {Name: "Gadget", Price: 20.00},
    {Name: "Tool", Price: 15.75},
}

// Mean price using specific AVX2 variant
mean := simd.MeanByFloat32x8(products, func(p Product) float32 {
    return p.Price
})
// 15.4167

type Metric struct {
    Value uint16
}

metrics := []Metric{
    {Value: 100},
    {Value: 200},
    {Value: 300},
    {Value: 400},
}

// Using AVX variant - works on all amd64
mean := simd.MeanByUint16x8(metrics, func(m Metric) uint16 {
    return m.Value
})
// 250

// Empty collection returns 0
type Item struct {
    Count int64
}

mean := simd.MeanByInt64([]Item{}, func(i Item) int64 {
    return i.Count
})
// 0