FFT buffer transformations for commons-math

doc/linear.md

@@ -0,0 +1 @@
+**TODO**

kmath-commons/build.gradle.kts

@@ -6,6 +6,7 @@ description = "Commons math binding for kmath"
 
 dependencies {
     api(project(":kmath-core"))
+    api(project(":kmath-sequential"))
     api("org.apache.commons:commons-math3:3.6.1")
     testImplementation("org.jetbrains.kotlin:kotlin-test")
     testImplementation("org.jetbrains.kotlin:kotlin-test-junit")

kmath-commons/src/main/kotlin/scientifik/kmath/transform/Transformations.kt

@@ -0,0 +1,63 @@
+package scientifik.kmath.transform
+
+import org.apache.commons.math3.transform.*
+import scientifik.kmath.operations.Complex
+import scientifik.kmath.structures.*
+
+
+/**
+ *
+ */
+object Transformations {
+
+    private fun Buffer<Complex>.toArray(): Array<org.apache.commons.math3.complex.Complex> =
+        Array(size) { org.apache.commons.math3.complex.Complex(get(it).re, get(it).im) }
+
+    private fun Buffer<Double>.asArray() = if (this is DoubleBuffer) {
+        array
+    } else {
+        DoubleArray(size) { i -> get(i) }
+    }
+
+    /**
+     * Create a virtual buffer on top of array
+     */
+    private fun Array<org.apache.commons.math3.complex.Complex>.asBuffer() = VirtualBuffer<Complex>(size) {
+        val value = get(it)
+        Complex(value.real, value.imaginary)
+    }
+
+    fun fourier(
+        normalization: DftNormalization = DftNormalization.STANDARD,
+        direction: TransformType = TransformType.FORWARD
+    ): BufferTransform<Complex, Complex> = {
+        FastFourierTransformer(normalization).transform(it.toArray(), direction).asBuffer()
+    }
+
+    fun realFourier(
+        normalization: DftNormalization = DftNormalization.STANDARD,
+        direction: TransformType = TransformType.FORWARD
+    ): BufferTransform<Double, Complex> = {
+        FastFourierTransformer(normalization).transform(it.asArray(), direction).asBuffer()
+    }
+
+    fun sine(
+        normalization: DstNormalization = DstNormalization.STANDARD_DST_I,
+        direction: TransformType = TransformType.FORWARD
+    ): BufferTransform<Double, Double> = {
+        FastSineTransformer(normalization).transform(it.asArray(), direction).asBuffer()
+    }
+
+    fun cosine(
+        normalization: DctNormalization = DctNormalization.STANDARD_DCT_I,
+        direction: TransformType = TransformType.FORWARD
+    ): BufferTransform<Double, Double> = {
+        FastCosineTransformer(normalization).transform(it.asArray(), direction).asBuffer()
+    }
+
+    fun hadamard(
+        direction: TransformType = TransformType.FORWARD
+    ): BufferTransform<Double, Double> = {
+        FastHadamardTransformer().transform(it.asArray(), direction).asBuffer()
+    }
+}

kmath-core/src/commonMain/kotlin/scientifik/kmath/structures/Buffers.kt

@@ -154,7 +154,7 @@ inline class DoubleBuffer(val array: DoubleArray) : MutableBuffer<Double> {
         array[index] = value
     }
 
-    override fun iterator(): Iterator<Double> = array.iterator()
+    override fun iterator() = array.iterator()
 
     override fun copy(): MutableBuffer<Double> = DoubleBuffer(array.copyOf())
 }
@@ -162,7 +162,6 @@ inline class DoubleBuffer(val array: DoubleArray) : MutableBuffer<Double> {
 @Suppress("FunctionName")
 inline fun DoubleBuffer(size: Int, init: (Int) -> Double) = DoubleBuffer(DoubleArray(size) { init(it) })
 
-
 /**
  * Transform buffer of doubles into array for high performance operations
  */
@@ -184,7 +183,7 @@ inline class ShortBuffer(val array: ShortArray) : MutableBuffer<Short> {
         array[index] = value
     }
 
-    override fun iterator(): Iterator<Short> = array.iterator()
+    override fun iterator() = array.iterator()
 
     override fun copy(): MutableBuffer<Short> = ShortBuffer(array.copyOf())
 
@@ -201,7 +200,7 @@ inline class IntBuffer(val array: IntArray) : MutableBuffer<Int> {
         array[index] = value
     }
 
-    override fun iterator(): Iterator<Int> = array.iterator()
+    override fun iterator() = array.iterator()
 
     override fun copy(): MutableBuffer<Int> = IntBuffer(array.copyOf())
 
@@ -218,7 +217,7 @@ inline class LongBuffer(val array: LongArray) : MutableBuffer<Long> {
         array[index] = value
     }
 
-    override fun iterator(): Iterator<Long> = array.iterator()
+    override fun iterator() = array.iterator()
 
     override fun copy(): MutableBuffer<Long> = LongBuffer(array.copyOf())
 
@@ -231,7 +230,7 @@ inline class ReadOnlyBuffer<T>(val buffer: MutableBuffer<T>) : Buffer<T> {
 
     override fun get(index: Int): T = buffer.get(index)
 
-    override fun iterator(): Iterator<T> = buffer.iterator()
+    override fun iterator() = buffer.iterator()
 }
 
 /**
@@ -260,3 +259,8 @@ fun <T> Buffer<T>.asReadOnly(): Buffer<T> = if (this is MutableBuffer) {
 } else {
     this
 }
+
+/**
+ * Typealias for buffer transformations
+ */
+typealias BufferTransform<T, R> = (Buffer<T>) -> Buffer<R>

kmath-sequential/src/commonMain/kotlin/scientifik/kmath/sequential/DoubleProcessors.kt

@@ -0,0 +1,7 @@
+package scientifik.kmath.sequential
+
+import kotlinx.coroutines.CoroutineScope
+
+//class FFTProcessor(scope: CoroutineScope): AbstractDoubleProcessor(scope){
+//
+//}

kmath-sequential/src/commonMain/kotlin/scientifik/kmath/sequential/DoubleStreaming.kt

@@ -7,13 +7,22 @@ import kotlinx.coroutines.channels.*
 import kotlinx.coroutines.isActive
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.sync.Mutex
+import scientifik.kmath.structures.Buffer
+import scientifik.kmath.structures.asBuffer
+import scientifik.kmath.structures.asSequence
+
+fun <T> Buffer<T>.asChannel(scope: CoroutineScope): ReceiveChannel<T> = scope.produce {
+    for (i in (0 until size)) {
+        send(get(i))
+    }
+}
 
 interface DoubleProducer : Producer<Double> {
-    suspend fun receiveArray(): DoubleArray
+    suspend fun receiveArray(): Buffer<Double>
 }
 
 interface DoubleConsumer : Consumer<Double> {
-    suspend fun sendArray(array: DoubleArray)
+    suspend fun sendArray(array: Buffer<Double>)
 }
 
 abstract class AbstractDoubleProducer(scope: CoroutineScope) : AbstractProducer<Double>(scope), DoubleProducer {
@@ -79,15 +88,15 @@ abstract class AbstractDoubleProcessor(scope: CoroutineScope) : AbstractProcesso
 class BasicDoubleProducer(
     scope: CoroutineScope,
     capacity: Int = Channel.UNLIMITED,
-    block: suspend ProducerScope<DoubleArray>.() -> Unit
+    block: suspend ProducerScope<Buffer<Double>>.() -> Unit
 ) : AbstractDoubleProducer(scope) {
 
 
     private val currentArray = atomic<ReceiveChannel<Double>?>(null)
-    private val channel: ReceiveChannel<DoubleArray> by lazy { produce(capacity = capacity, block = block) }
+    private val channel: ReceiveChannel<Buffer<Double>> by lazy { produce(capacity = capacity, block = block) }
     private val cachingChannel by lazy {
         channel.map {
-            it.also { doubles -> currentArray.lazySet(doubles.asChannel()) }
+            it.also { doubles -> currentArray.lazySet(doubles.asChannel(this)) }
         }
     }
 
@@ -97,40 +106,39 @@ class BasicDoubleProducer(
         }
     }
 
-    override suspend fun receiveArray(): DoubleArray = cachingChannel.receive()
+    override suspend fun receiveArray(): Buffer<Double> = cachingChannel.receive()
 
-    override suspend fun receive(): Double = (currentArray.value ?: cachingChannel.receive().asChannel()).receive()
+    override suspend fun receive(): Double = (currentArray.value ?: cachingChannel.receive().asChannel(this)).receive()
 }
 
 
 class DoubleReducer<S>(
     scope: CoroutineScope,
     initialState: S,
-    val fold: suspend (S, DoubleArray) -> S
+    val fold: suspend (S, Buffer<Double>) -> S
 ) : AbstractDoubleConsumer(scope) {
 
     var state: S = initialState
         private set
 
-    private val mutex = Mutex()
-
-    override suspend fun sendArray(array: DoubleArray) {
+    override suspend fun sendArray(array: Buffer<Double>) {
         state = fold(state, array)
     }
 
-    override suspend fun send(value: Double) = sendArray(doubleArrayOf(value))
+    override suspend fun send(value: Double) = sendArray(doubleArrayOf(value).asBuffer())
 }
 
 /**
  * Convert an array to single element producer, splitting it in chunks if necessary
  */
-fun DoubleArray.produce(scope: CoroutineScope = GlobalScope, chunkSize: Int = Int.MAX_VALUE) = if (size < chunkSize) {
+fun Buffer<Double>.produce(scope: CoroutineScope = GlobalScope, chunkSize: Int = Int.MAX_VALUE) =
+    if (size < chunkSize) {
         BasicDoubleProducer(scope) { send(this@produce) }
-} else {
+    } else {
         BasicDoubleProducer(scope) {
             //TODO optimize this!
             asSequence().chunked(chunkSize).forEach {
-            send(it.toDoubleArray())
+                send(it.asBuffer())
+            }
         }
     }
-}