Integration between MST and Symja IExpr

CHANGELOG.md

@@ -2,18 +2,19 @@
 
 ## [Unreleased]
 ### Added
-- ScaleOperations interface
-- Field extends ScaleOperations
+- `ScaleOperations` interface
+- `Field` extends `ScaleOperations`
 - Basic integration API
 - Basic MPP distributions and samplers
-- bindSymbolOrNull
+- `bindSymbolOrNull`
 - Blocking chains and Statistics
 - Multiplatform integration
 - Integration for any Field element
 - Extended operations for ND4J fields
 - Jupyter Notebook integration module (kmath-jupyter)
 - `@PerformancePitfall` annotation to mark possibly slow API
-- BigInt operation performance improvement and fixes by @zhelenskiy (#328)
+- `BigInt` operation performance improvement and fixes by @zhelenskiy (#328)
+- Integration between `MST` and Symja `IExpr`
 
 ### Changed
 - Exponential operations merged with hyperbolic functions

examples/build.gradle.kts

@@ -26,7 +26,7 @@ dependencies {
     implementation(project(":kmath-ejml"))
     implementation(project(":kmath-nd4j"))
     implementation(project(":kmath-tensors"))
-
+    implementation(project(":kmath-symja"))
     implementation(project(":kmath-for-real"))
 
     implementation("org.nd4j:nd4j-native:1.0.0-beta7")

examples/src/main/kotlin/space/kscience/kmath/ast/kotlingradSupport.kt

@@ -5,25 +5,23 @@
 
 package space.kscience.kmath.ast
 
-import space.kscience.kmath.asm.compileToExpression
 import space.kscience.kmath.expressions.derivative
 import space.kscience.kmath.expressions.invoke
-import space.kscience.kmath.expressions.symbol
-import space.kscience.kmath.kotlingrad.toDiffExpression
+import space.kscience.kmath.expressions.Symbol.Companion.x
+import space.kscience.kmath.expressions.toExpression
+import space.kscience.kmath.kotlingrad.toKotlingradExpression
 import space.kscience.kmath.operations.DoubleField
 
 /**
  * In this example, x^2-4*x-44 function is differentiated with Kotlin∇, and the autodiff result is compared with
- * valid derivative.
+ * valid derivative in a certain point.
  */
 fun main() {
-    val x by symbol
-
-    val actualDerivative = "x^2-4*x-44".parseMath()
-        .toDiffExpression(DoubleField)
+    val actualDerivative = "x^2-4*x-44"
+        .parseMath()
+        .toKotlingradExpression(DoubleField)
         .derivative(x)
 
-
-    val expectedDerivative = "2*x-4".parseMath().compileToExpression(DoubleField)
-    assert(actualDerivative(x to 123.0) == expectedDerivative(x to 123.0))
+    val expectedDerivative = "2*x-4".parseMath().toExpression(DoubleField)
+    check(actualDerivative(x to 123.0) == expectedDerivative(x to 123.0))
 }

examples/src/main/kotlin/space/kscience/kmath/ast/symjaSupport.kt

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2018-2021 KMath contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package space.kscience.kmath.ast
+
+import space.kscience.kmath.expressions.Symbol.Companion.x
+import space.kscience.kmath.expressions.derivative
+import space.kscience.kmath.expressions.invoke
+import space.kscience.kmath.expressions.toExpression
+import space.kscience.kmath.operations.DoubleField
+import space.kscience.kmath.symja.toSymjaExpression
+
+/**
+ * In this example, x^2-4*x-44 function is differentiated with Symja, and the autodiff result is compared with
+ * valid derivative in a certain point.
+ */
+fun main() {
+    val actualDerivative = "x^2-4*x-44"
+        .parseMath()
+        .toSymjaExpression(DoubleField)
+        .derivative(x)
+
+    val expectedDerivative = "2*x-4".parseMath().toExpression(DoubleField)
+    check(actualDerivative(x to 123.0) == expectedDerivative(x to 123.0))
+}

kmath-kotlingrad/src/main/kotlin/space/kscience/kmath/kotlingrad/KotlingradExpression.kt

@@ -39,7 +39,7 @@ public class KotlingradExpression<T : Number, A : NumericAlgebra<T>>(
 }
 
 /**
- * Wraps this [MST] into [KotlingradExpression].
+ * Wraps this [MST] into [KotlingradExpression] in the context of [algebra].
  */
-public fun <T : Number, A : NumericAlgebra<T>> MST.toDiffExpression(algebra: A): KotlingradExpression<T, A> =
+public fun <T : Number, A : NumericAlgebra<T>> MST.toKotlingradExpression(algebra: A): KotlingradExpression<T, A> =
     KotlingradExpression(algebra, this)

kmath-symja/build.gradle.kts

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2018-2021 KMath contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+plugins {
+    kotlin("jvm")
+    id("ru.mipt.npm.gradle.common")
+}
+
+description = "Symja integration module"
+
+dependencies {
+    api("org.matheclipse:matheclipse-core:2.0.0-SNAPSHOT")
+    api(project(":kmath-core"))
+    testImplementation("org.slf4j:slf4j-simple:1.7.30")
+}
+
+readme {
+    maturity = ru.mipt.npm.gradle.Maturity.PROTOTYPE
+}

kmath-symja/src/main/kotlin/space/kscience/kmath/symja/SymjaExpression.kt

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2018-2021 KMath contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package space.kscience.kmath.symja
+
+import org.matheclipse.core.eval.ExprEvaluator
+import org.matheclipse.core.expression.F
+import space.kscience.kmath.expressions.DifferentiableExpression
+import space.kscience.kmath.expressions.MST
+import space.kscience.kmath.expressions.Symbol
+import space.kscience.kmath.expressions.interpret
+import space.kscience.kmath.operations.NumericAlgebra
+
+public class SymjaExpression<T : Number, A : NumericAlgebra<T>>(
+    public val algebra: A,
+    public val mst: MST,
+    public val evaluator: ExprEvaluator = DEFAULT_EVALUATOR,
+) : DifferentiableExpression<T, SymjaExpression<T, A>> {
+    public override fun invoke(arguments: Map<Symbol, T>): T = mst.interpret(algebra, arguments)
+
+    public override fun derivativeOrNull(symbols: List<Symbol>): SymjaExpression<T, A> = SymjaExpression(
+        algebra,
+        symbols.map(Symbol::toIExpr).fold(mst.toIExpr(), F::D).toMst(evaluator),
+        evaluator,
+    )
+}
+
+/**
+ * Wraps this [MST] into [SymjaExpression] in the context of [algebra].
+ */
+public fun <T : Number, A : NumericAlgebra<T>> MST.toSymjaExpression(algebra: A): SymjaExpression<T, A> =
+    SymjaExpression(algebra, this)

kmath-symja/src/main/kotlin/space/kscience/kmath/symja/adapters.kt

@@ -0,0 +1,95 @@
+/*
+ * Copyright 2018-2021 KMath contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package space.kscience.kmath.symja
+
+import org.matheclipse.core.eval.ExprEvaluator
+import org.matheclipse.core.expression.ComplexNum
+import org.matheclipse.core.expression.F
+import org.matheclipse.core.interfaces.IExpr
+import org.matheclipse.core.interfaces.ISymbol
+import space.kscience.kmath.expressions.MST
+import space.kscience.kmath.expressions.MstExtendedField
+import space.kscience.kmath.expressions.Symbol
+import space.kscience.kmath.operations.*
+
+internal val DEFAULT_EVALUATOR = ExprEvaluator(false, 100)
+
+/**
+ * Matches the given [IExpr] instance to appropriate [MST] node or evaluates it with [evaluator].
+ */
+public fun IExpr.toMst(evaluator: ExprEvaluator = DEFAULT_EVALUATOR): MST = MstExtendedField {
+    when {
+        isPlus -> first().toMst(evaluator) + second().toMst(evaluator)
+        isSin -> sin(first().toMst(evaluator))
+        isSinh -> sinh(first().toMst(evaluator))
+        isCos -> cos(first().toMst(evaluator))
+        isCosh -> cosh(first().toMst(evaluator))
+        isTan -> tan(first().toMst(evaluator))
+        isTanh -> tanh(first().toMst(evaluator))
+        isArcSin -> asin(first().toMst(evaluator))
+        isArcCos -> acos(first().toMst(evaluator))
+        isArcTan -> atan(first().toMst(evaluator))
+        isArcTanh -> atanh(first().toMst(evaluator))
+        isE -> bindSymbol("e")
+        isPi -> bindSymbol("pi")
+        isTimes -> first().toMst(evaluator) * second().toMst(evaluator)
+        isOne -> one
+        isZero -> zero
+        isImaginaryUnit -> bindSymbol("i")
+        isMinusOne -> -one
+        this@toMst is ISymbol -> bindSymbol(symbolName)
+        isPower -> power(first().toMst(evaluator), evaluator.evalf(second()))
+        isExp -> exp(first().toMst(evaluator))
+        isNumber -> number(evaluator.evalf(this@toMst))
+        this@toMst === F.NIL -> error("NIL cannot be converted to MST")
+        else -> evaluator.eval(this@toMst.toString()).toMst(evaluator)
+    }
+}
+
+/**
+ * Matches the given [MST] instance to appropriate [IExpr] node, only standard operations and symbols (which are
+ * present in, say, [MstExtendedField]) are supported.
+ */
+public fun MST.toIExpr(): IExpr = when (this) {
+    is MST.Numeric -> F.symjify(value)
+
+    is Symbol -> when (identity) {
+        "e" -> F.E
+        "pi" -> F.Pi
+        "i" -> ComplexNum.I
+        else -> F.Dummy(identity)
+    }
+
+    is MST.Unary -> when (operation) {
+        GroupOperations.PLUS_OPERATION -> value.toIExpr()
+        GroupOperations.MINUS_OPERATION -> F.Negate(value.toIExpr())
+        TrigonometricOperations.SIN_OPERATION -> F.Sin(value.toIExpr())
+        TrigonometricOperations.COS_OPERATION -> F.Cos(value.toIExpr())
+        TrigonometricOperations.TAN_OPERATION -> F.Tan(value.toIExpr())
+        TrigonometricOperations.ASIN_OPERATION -> F.ArcSin(value.toIExpr())
+        TrigonometricOperations.ACOS_OPERATION -> F.ArcCos(value.toIExpr())
+        TrigonometricOperations.ATAN_OPERATION -> F.ArcTan(value.toIExpr())
+        ExponentialOperations.SINH_OPERATION -> F.Sinh(value.toIExpr())
+        ExponentialOperations.COSH_OPERATION -> F.Cosh(value.toIExpr())
+        ExponentialOperations.TANH_OPERATION -> F.Tanh(value.toIExpr())
+        ExponentialOperations.ASINH_OPERATION -> F.ArcSinh(value.toIExpr())
+        ExponentialOperations.ACOSH_OPERATION -> F.ArcCosh(value.toIExpr())
+        ExponentialOperations.ATANH_OPERATION -> F.ArcTanh(value.toIExpr())
+        PowerOperations.SQRT_OPERATION -> F.Sqrt(value.toIExpr())
+        ExponentialOperations.EXP_OPERATION -> F.Exp(value.toIExpr())
+        ExponentialOperations.LN_OPERATION -> F.Log(value.toIExpr())
+        else -> error("Unary operation $operation not defined in $this")
+    }
+
+    is MST.Binary -> when (operation) {
+        GroupOperations.PLUS_OPERATION -> left.toIExpr() + right.toIExpr()
+        GroupOperations.MINUS_OPERATION -> left.toIExpr() - right.toIExpr()
+        RingOperations.TIMES_OPERATION -> left.toIExpr() * right.toIExpr()
+        FieldOperations.DIV_OPERATION -> F.Divide(left.toIExpr(), right.toIExpr())
+        PowerOperations.POW_OPERATION -> F.Power(left.toIExpr(), F.symjify((right as MST.Numeric).value))
+        else -> error("Binary operation $operation not defined in $this")
+    }
+}

settings.gradle.kts

@@ -42,6 +42,7 @@ include(
     ":kmath-kotlingrad",
     ":kmath-tensors",
     ":kmath-jupyter",
+    ":kmath-symja",
     ":examples",
     ":benchmarks"
 )