Another histogram refactor

build.gradle.kts

@@ -11,7 +11,7 @@ allprojects {
     }
 
     group = "space.kscience"
-    version = "0.3.0-dev-20"
+    version = "0.3.0-dev-21"
 }
 
 subprojects {

buildSrc/gradle.properties

@@ -5,4 +5,4 @@
 
 kotlin.code.style=official
 
-toolsVersion=0.11.1-kotlin-1.6.10
+toolsVersion=0.11.2-kotlin-1.6.10

kmath-core/src/commonMain/kotlin/space/kscience/kmath/domains/HyperSquareDomain.kt

@@ -7,6 +7,7 @@ package space.kscience.kmath.domains
 import space.kscience.kmath.linear.Point
 import space.kscience.kmath.misc.UnstableKMathAPI
 import space.kscience.kmath.structures.Buffer
+import space.kscience.kmath.structures.DoubleBuffer
 import space.kscience.kmath.structures.indices
 
 /**
@@ -16,9 +17,17 @@ import space.kscience.kmath.structures.indices
  * @author Alexander Nozik
  */
 @UnstableKMathAPI
-public class HyperSquareDomain(private val lower: Buffer<Double>, private val upper: Buffer<Double>) : DoubleDomain {
+public class HyperSquareDomain(public val lower: Buffer<Double>, public val upper: Buffer<Double>) : DoubleDomain {
+    init {
+        require(lower.size == upper.size) {
+            "Domain borders size mismatch. Lower borders size is ${lower.size}, but upper borders size is ${upper.size}"
+        }
+    }
+
     override val dimension: Int get() = lower.size
 
+    public val center: DoubleBuffer get() = DoubleBuffer(dimension) { (lower[it] + upper[it]) / 2.0 }
+
     override operator fun contains(point: Point<Double>): Boolean = point.indices.all { i ->
         point[i] in lower[i]..upper[i]
     }

kmath-histograms/src/commonMain/kotlin/space/kscience/kmath/histogram/DoubleHistogramSpace.kt

@@ -5,7 +5,6 @@
 
 package space.kscience.kmath.histogram
 
-import space.kscience.kmath.domains.Domain
 import space.kscience.kmath.domains.HyperSquareDomain
 import space.kscience.kmath.misc.UnstableKMathAPI
 import space.kscience.kmath.nd.*
@@ -13,6 +12,9 @@ import space.kscience.kmath.operations.DoubleField
 import space.kscience.kmath.structures.*
 import kotlin.math.floor
 
+/**
+ * Multivariate histogram space for hyper-square real-field bins.
+ */
 public class DoubleHistogramSpace(
     private val lower: Buffer<Double>,
     private val upper: Buffer<Double>,
@@ -47,7 +49,7 @@ public class DoubleHistogramSpace(
     }
 
     @OptIn(UnstableKMathAPI::class)
-    override fun getDomain(index: IntArray): Domain<Double> {
+    override fun getDomain(index: IntArray): HyperSquareDomain {
         val lowerBoundary = index.mapIndexed { axis, i ->
             when (i) {
                 0 -> Double.NEGATIVE_INFINITY
@@ -67,8 +69,13 @@ public class DoubleHistogramSpace(
         return HyperSquareDomain(lowerBoundary, upperBoundary)
     }
 
+    @OptIn(UnstableKMathAPI::class)
+    public val Bin<Double>.domain: HyperSquareDomain
+        get() = (this as? DomainBin<Double>)?.domain as? HyperSquareDomain
+            ?: error("Im a teapot. This is not my bin")
 
-    override fun produceBin(index: IntArray, value: Double): Bin<Double> {
+    @OptIn(UnstableKMathAPI::class)
+    override fun produceBin(index: IntArray, value: Double): DomainBin<Double> {
         val domain = getDomain(index)
         return DomainBin(domain, value)
     }
@@ -96,7 +103,9 @@ public class DoubleHistogramSpace(
          *)
          *```
          */
-        public fun fromRanges(vararg ranges: ClosedFloatingPointRange<Double>): DoubleHistogramSpace = DoubleHistogramSpace(
+        public fun fromRanges(
+            vararg ranges: ClosedFloatingPointRange<Double>,
+        ): DoubleHistogramSpace = DoubleHistogramSpace(
             ranges.map(ClosedFloatingPointRange<Double>::start).asBuffer(),
             ranges.map(ClosedFloatingPointRange<Double>::endInclusive).asBuffer()
         )
@@ -110,21 +119,22 @@ public class DoubleHistogramSpace(
          *)
          *```
          */
-        public fun fromRanges(vararg ranges: Pair<ClosedFloatingPointRange<Double>, Int>): DoubleHistogramSpace =
+        public fun fromRanges(
-            DoubleHistogramSpace(
+            vararg ranges: Pair<ClosedFloatingPointRange<Double>, Int>,
-                ListBuffer(
+        ): DoubleHistogramSpace = DoubleHistogramSpace(
-                    ranges
+            ListBuffer(
-                        .map(Pair<ClosedFloatingPointRange<Double>, Int>::first)
+                ranges
-                        .map(ClosedFloatingPointRange<Double>::start)
+                    .map(Pair<ClosedFloatingPointRange<Double>, Int>::first)
-                ),
+                    .map(ClosedFloatingPointRange<Double>::start)
+            ),
 
-                ListBuffer(
+            ListBuffer(
-                    ranges
+                ranges
-                        .map(Pair<ClosedFloatingPointRange<Double>, Int>::first)
+                    .map(Pair<ClosedFloatingPointRange<Double>, Int>::first)
-                        .map(ClosedFloatingPointRange<Double>::endInclusive)
+                    .map(ClosedFloatingPointRange<Double>::endInclusive)
-                ),
+            ),
 
-                ranges.map(Pair<ClosedFloatingPointRange<Double>, Int>::second).toIntArray()
+            ranges.map(Pair<ClosedFloatingPointRange<Double>, Int>::second).toIntArray()
-            )
+        )
     }
 }

kmath-histograms/src/commonMain/kotlin/space/kscience/kmath/histogram/IndexedHistogramSpace.kt

@@ -7,7 +7,6 @@ package space.kscience.kmath.histogram
 
 import space.kscience.kmath.domains.Domain
 import space.kscience.kmath.linear.Point
-import space.kscience.kmath.misc.UnstableKMathAPI
 import space.kscience.kmath.nd.DefaultStrides
 import space.kscience.kmath.nd.FieldND
 import space.kscience.kmath.nd.Shape
@@ -24,22 +23,21 @@ public data class DomainBin<in T : Comparable<T>>(
     override val value: Number,
 ) : Bin<T>, Domain<T> by domain
 
-@OptIn(UnstableKMathAPI::class)
 public class IndexedHistogram<T : Comparable<T>, V : Any>(
-    public val context: IndexedHistogramSpace<T, V>,
+    public val histogramSpace: IndexedHistogramSpace<T, V>,
     public val values: StructureND<V>,
 ) : Histogram<T, Bin<T>> {
 
     override fun get(point: Point<T>): Bin<T>? {
-        val index = context.getIndex(point) ?: return null
+        val index = histogramSpace.getIndex(point) ?: return null
-        return context.produceBin(index, values[index])
+        return histogramSpace.produceBin(index, values[index])
     }
 
-    override val dimension: Int get() = context.shape.size
+    override val dimension: Int get() = histogramSpace.shape.size
 
     override val bins: Iterable<Bin<T>>
-        get() = DefaultStrides(context.shape).asSequence().map {
+        get() = DefaultStrides(histogramSpace.shape).asSequence().map {
-            context.produceBin(it, values[it])
+            histogramSpace.produceBin(it, values[it])
         }.asIterable()
 }
 
@@ -67,13 +65,13 @@ public interface IndexedHistogramSpace<T : Comparable<T>, V : Any>
     public fun produce(builder: HistogramBuilder<T>.() -> Unit): IndexedHistogram<T, V>
 
     override fun add(left: IndexedHistogram<T, V>, right: IndexedHistogram<T, V>): IndexedHistogram<T, V> {
-        require(left.context == this) { "Can't operate on a histogram produced by external space" }
+        require(left.histogramSpace == this) { "Can't operate on a histogram produced by external space" }
-        require(right.context == this) { "Can't operate on a histogram produced by external space" }
+        require(right.histogramSpace == this) { "Can't operate on a histogram produced by external space" }
         return IndexedHistogram(this, histogramValueSpace { left.values + right.values })
     }
 
     override fun scale(a: IndexedHistogram<T, V>, value: Double): IndexedHistogram<T, V> {
-        require(a.context == this) { "Can't operate on a histogram produced by external space" }
+        require(a.histogramSpace == this) { "Can't operate on a histogram produced by external space" }
         return IndexedHistogram(this, histogramValueSpace { a.values * value })
     }
 

kmath-histograms/src/commonMain/kotlin/space/kscience/kmath/histogram/UnivariateHistogram.kt

@@ -37,26 +37,6 @@ public class UnivariateBin(
 public interface UnivariateHistogram : Histogram<Double, UnivariateBin> {
     public operator fun get(value: Double): UnivariateBin?
     override operator fun get(point: Buffer<Double>): UnivariateBin? = get(point[0])
-
-    public companion object {
-        /**
-         * Build and fill a [UnivariateHistogram]. Returns a read-only histogram.
-         */
-        public inline fun uniform(
-            binSize: Double,
-            start: Double = 0.0,
-            builder: UnivariateHistogramBuilder.() -> Unit,
-        ): UnivariateHistogram = TreeHistogramSpace.uniform(binSize, start).fill(builder)
-
-        /**
-         * Build and fill a histogram with custom borders. Returns a read-only histogram.
-         */
-        public inline fun custom(
-            borders: DoubleArray,
-            builder: UnivariateHistogramBuilder.() -> Unit,
-        ): UnivariateHistogram = TreeHistogramSpace.custom(borders).fill(builder)
-
-    }
 }
 
 @UnstableKMathAPI

kmath-histograms/src/jvmMain/kotlin/space/kscience/kmath/histogram/TreeHistogramSpace.kt

@@ -49,7 +49,9 @@ internal class TreeHistogramBuilder(val binFactory: (Double) -> UnivariateDomain
     fun createBin(value: Double): BinCounter {
         val binDefinition = binFactory(value)
         val newBin = BinCounter(binDefinition)
-        synchronized(this) { bins[binDefinition.center] = newBin }
+        synchronized(this) {
+            bins[binDefinition.center] = newBin
+        }
         return newBin
     }
 
@@ -131,6 +133,24 @@ public class TreeHistogramSpace(
     override val zero: UnivariateHistogram by lazy { fill { } }
 
     public companion object {
+        /**
+         * Build and fill a [UnivariateHistogram]. Returns a read-only histogram.
+         */
+        public inline fun uniform(
+            binSize: Double,
+            start: Double = 0.0,
+            builder: UnivariateHistogramBuilder.() -> Unit,
+        ): UnivariateHistogram = uniform(binSize, start).fill(builder)
+
+        /**
+         * Build and fill a histogram with custom borders. Returns a read-only histogram.
+         */
+        public inline fun custom(
+            borders: DoubleArray,
+            builder: UnivariateHistogramBuilder.() -> Unit,
+        ): UnivariateHistogram = custom(borders).fill(builder)
+
+
         /**
          * Build and fill a [UnivariateHistogram]. Returns a read-only histogram.
          */

kmath-histograms/src/jvmTest/kotlin/space/kscience/kmath/histogram/TreeHistogramTest.kt

@@ -13,7 +13,7 @@ class TreeHistogramTest {
 
     @Test
     fun normalFill() {
-        val histogram = UnivariateHistogram.uniform(0.1) {
+        val histogram = TreeHistogramSpace.uniform(0.1) {
             repeat(100_000) {
                 putValue(Random.nextDouble())
             }