Sequential operations
This commit is contained in:
parent
1e99e89c4c
commit
002ddbee48
@ -1,25 +1,50 @@
|
||||
package scientifik.kmath.sequential
|
||||
|
||||
import kotlinx.atomicfu.atomic
|
||||
import kotlinx.atomicfu.atomicArrayOfNulls
|
||||
import kotlinx.atomicfu.getAndUpdate
|
||||
import kotlinx.coroutines.GlobalScope
|
||||
import kotlinx.coroutines.channels.Channel
|
||||
import kotlinx.coroutines.channels.ReceiveChannel
|
||||
import scientifik.kmath.operations.Space
|
||||
|
||||
/**
|
||||
* An object with a state that accumulates incoming elements
|
||||
*/
|
||||
interface Accumulator<in T> {
|
||||
//PENDING use suspend operations?
|
||||
/**
|
||||
* Push a value to accumulator. Blocks if [Accumulator] can't access any more elements at that time
|
||||
*/
|
||||
fun push(value: T)
|
||||
}
|
||||
|
||||
fun <T> Accumulator<T>.pushAll(values: Iterable<T>) {
|
||||
values.forEach { push(it) }
|
||||
/**
|
||||
* Does the same as [push], but suspends instead of blocking if accumulator is full
|
||||
*/
|
||||
suspend fun send(value: T) = push(value)
|
||||
}
|
||||
|
||||
/**
|
||||
* Generic thread-safe summator
|
||||
* Push all elements to accumulator
|
||||
*/
|
||||
class GenericSum<T : Any>(val context: Space<T>) : Accumulator<T> {
|
||||
fun <T> Accumulator<T>.pushAll(values: Iterable<T>) {
|
||||
for (value in values) {
|
||||
push(value)
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Offer all elements from channel to accumulator
|
||||
*/
|
||||
suspend fun <T> Accumulator<T>.offerAll(channel: ReceiveChannel<T>) {
|
||||
for (value in channel) {
|
||||
send(value)
|
||||
}
|
||||
}
|
||||
|
||||
/**
|
||||
* Generic thread-safe average
|
||||
*/
|
||||
class GenericMean<T : Any>(val context: Space<T>) : Accumulator<T> {
|
||||
//TODO add guard against overflow
|
||||
val counter = atomic(0)
|
||||
val sum = atomic(context.zero)
|
||||
|
@ -16,6 +16,6 @@ inline fun <T, C, R> Array<T>.reduce(context: C, crossinline reducer: Reducer<T,
|
||||
|
||||
object Reducers {
|
||||
fun <T : Any> mean(): Reducer<T, Space<T>, T> = { context, data ->
|
||||
data.fold(GenericSum(context)) { sum, value -> sum.apply { push(value) } }.value
|
||||
data.fold(GenericMean(context)) { sum, value -> sum.apply { push(value) } }.value
|
||||
}
|
||||
}
|
@ -0,0 +1,28 @@
|
||||
package scientifik.kmath.sequential
|
||||
|
||||
import kotlinx.coroutines.channels.Channel
|
||||
import kotlinx.coroutines.channels.ReceiveChannel
|
||||
import scientifik.kmath.operations.Space
|
||||
import scientifik.kmath.structures.runBlocking
|
||||
import java.util.*
|
||||
|
||||
/**
|
||||
* A moving average with fixed window
|
||||
*/
|
||||
class MovingAverage<T : Any>(val window: Int, val context: Space<T>) : Accumulator<T> {
|
||||
private val outputChannel = Channel<T>()
|
||||
private val queue = ArrayDeque<T>(window)
|
||||
|
||||
override suspend fun send(value: T) {
|
||||
queue.add(value)
|
||||
if (queue.size == window) {
|
||||
val sum = queue.fold(context.zero) { a, b -> context.run { a + b } }
|
||||
outputChannel.send(context.run { sum / window })
|
||||
queue.pop()
|
||||
}
|
||||
}
|
||||
|
||||
override fun push(value: T) = runBlocking { send(value) }
|
||||
|
||||
val output: ReceiveChannel<T> = outputChannel
|
||||
}
|
@ -1,7 +1,6 @@
|
||||
package scientifik.kmath.chains
|
||||
package scientifik.kmath.sequential
|
||||
|
||||
import kotlinx.coroutines.runBlocking
|
||||
import scientifik.kmath.sequential.Chain
|
||||
import kotlin.sequences.Sequence
|
||||
|
||||
/**
|
Loading…
Reference in New Issue
Block a user