kmath-functions/src/commonMain/kotlin/space/kscience/kmath/functions/LabeledPolynomial.kt

@@ -177,14 +177,17 @@ public class LabeledPolynomialSpace<C, A : Ring<C>>(
      * The operation is equivalent to sum of [other] copies of [this].
      */
     public override operator fun LabeledPolynomial<C>.times(other: Int): LabeledPolynomial<C> =
-        if (other == 0) zero
+        when(other) {
-        else LabeledPolynomial(
+            0 -> zero
+            1 -> this
+            else -> LabeledPolynomial(
                 coefficients
                     .toMutableMap()
                     .apply {
                         for (degs in keys) this[degs] = this[degs]!! * other
                     }
             )
+        }
 
     /**
      * Returns sum of the integer represented as a polynomial and the polynomial.
@@ -210,7 +213,7 @@ public class LabeledPolynomialSpace<C, A : Ring<C>>(
      * The operation is equivalent to subtraction [this] copies of unit polynomial from [other].
      */
     public override operator fun Int.minus(other: LabeledPolynomial<C>): LabeledPolynomial<C> =
-        if (this == 0) other
+        if (this == 0) -other
         else with(other.coefficients) {
             if (isEmpty()) LabeledPolynomialAsIs(mapOf(emptyMap<Symbol, UInt>() to this@minus.asConstant()))
             else LabeledPolynomialAsIs(
@@ -230,14 +233,17 @@ public class LabeledPolynomialSpace<C, A : Ring<C>>(
      * The operation is equivalent to sum of [this] copies of [other].
      */
     public override operator fun Int.times(other: LabeledPolynomial<C>): LabeledPolynomial<C> =
-        if (this == 0) zero
+        when(this) {
-        else LabeledPolynomial(
+            0 -> zero
+            1 -> other
+            else -> LabeledPolynomial(
                 other.coefficients
                     .toMutableMap()
                     .apply {
                         for (degs in keys) this[degs] = this@times * this[degs]!!
                     }
             )
+        }
 
     /**
      * Converts the integer [value] to polynomial.
@@ -360,8 +366,6 @@ public class LabeledPolynomialSpace<C, A : Ring<C>>(
             else LabeledPolynomialAsIs(
                 toMutableMap()
                     .apply {
-                        forEach { (degs, c) -> if(degs.isNotEmpty()) this[degs] = -c }
-
                         val degs = emptyMap<Symbol, UInt>()
 
                         this[degs] = getOrElse(degs) { constantZero } - other

kmath-functions/src/commonMain/kotlin/space/kscience/kmath/functions/labeledConstructors.kt

@@ -302,6 +302,7 @@ public class DSL1LabeledPolynomialTermSignatureBuilder {
      * Declaring another power of the same variable will increase its degree by received degree.
      */
     public infix fun Symbol.inPowerOf(deg: UInt) {
+        if (deg == 0u) return
         signature[this] = signature.getOrElse(this) { 0u } + deg
     }
     /**

kmath-functions/src/commonTest/kotlin/space/kscience/kmath/functions/LabeledConstructorsTest.kt

@@ -0,0 +1,129 @@
+/*
+ * 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.functions
+
+import space.kscience.kmath.expressions.Symbol
+import space.kscience.kmath.expressions.symbol
+import space.kscience.kmath.misc.UnstableKMathAPI
+import space.kscience.kmath.operations.algebra
+import space.kscience.kmath.operations.invoke
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+class LabeledConstructorsTest {
+    val x by symbol
+    val y by symbol
+    val z by symbol
+    val t by symbol
+    
+    @Test
+    @UnstableKMathAPI
+    fun testDSL1() {
+        assertEquals(
+            LabeledPolynomialAsIs(
+                mapOf(x to 2u, z to 3u) to 5,
+                mapOf(y to 1u) to -6,
+            ),
+            Int.algebra.labeledPolynomialSpace {
+                LabeledPolynomialDSL1 {
+                    5 { x pow 2u; z pow 3u }
+                    (-6) { y pow 1u }
+                }
+            },
+            "test 1"
+        )
+        assertEquals(
+            LabeledPolynomialAsIs(
+                mapOf<Symbol, UInt>() to -1,
+            ),
+            Int.algebra.labeledPolynomialSpace {
+                LabeledPolynomialDSL1 {
+                    5 { }
+                    (-6) { }
+                }
+            },
+            "test 2"
+        )
+        assertEquals(
+            LabeledPolynomialAsIs(
+                mapOf(x to 2u) to -1,
+            ),
+            Int.algebra.labeledPolynomialSpace {
+                LabeledPolynomialDSL1 {
+                    5 { x pow 1u; x pow 1u }
+                    (-6) { x pow 2u }
+                }
+            },
+            "test 3"
+        )
+        assertEquals(
+            LabeledPolynomialAsIs(
+                mapOf(x to 2u) to -1,
+            ),
+            Int.algebra.labeledPolynomialSpace {
+                LabeledPolynomialDSL1 {
+                    5 { x pow 1u; x pow 1u }
+                    (-6) { x pow 2u; z pow 0u }
+                }
+            },
+            "test 3"
+        )
+    }
+    @Test
+    @UnstableKMathAPI
+    fun testFabric() {
+        assertEquals(
+            LabeledPolynomialAsIs(
+                mapOf(x to 2u, z to 3u) to 5,
+                mapOf(y to 1u) to -6,
+            ),
+            Int.algebra {
+                LabeledPolynomial(
+                    mapOf(x to 2u, z to 3u) to 5,
+                    mapOf(y to 1u) to -6,
+                )
+            },
+            "test 1"
+        )
+        assertEquals(
+            LabeledPolynomialAsIs(
+                mapOf(x to 2u, z to 3u) to 5,
+                mapOf(y to 1u) to -6,
+            ),
+            Int.algebra {
+                LabeledPolynomial(
+                    mapOf(x to 2u, y to 0u, z to 3u, t to 0u) to 5,
+                    mapOf(x to 0u, y to 1u, z to 0u, t to 0u) to -6,
+                )
+            },
+            "test 2"
+        )
+        assertEquals(
+            LabeledPolynomialAsIs(
+                mapOf<Symbol, UInt>() to -1,
+            ),
+            Int.algebra {
+                LabeledPolynomial(
+                    mapOf(x to 0u) to 5,
+                    mapOf(y to 0u, z to 0u) to -6,
+                )
+            },
+            "test 3"
+        )
+        assertEquals(
+            LabeledPolynomialAsIs(
+                mapOf<Symbol, UInt>() to 0,
+            ),
+            Int.algebra {
+                LabeledPolynomial(
+                    mapOf(x to 0u) to 5,
+                    mapOf(z to 0u, t to 0u) to -5,
+                )
+            },
+            "test 4"
+        )
+    }
+}

kmath-functions/src/commonTest/kotlin/space/kscience/kmath/functions/NumberedPolynomialTest.kt

@@ -7,14 +7,19 @@
 
 package space.kscience.kmath.functions
 
-import space.kscience.kmath.misc.UnstableKMathAPI
+import space.kscience.kmath.test.misc.IntModuloRing
-import space.kscience.kmath.test.misc.*
+import space.kscience.kmath.test.misc.Rational
-import kotlin.test.*
+import space.kscience.kmath.test.misc.RationalField
+import space.kscience.kmath.test.misc.m
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertSame
+import kotlin.test.fail
 
 
-@UnstableKMathAPI
 class NumberedPolynomialTest {
-    private val o = Rational(0)
+    val o = Rational(0)
+
     @Test
     fun test_Polynomial_Int_plus() {
         RationalField.numberedPolynomialSpace {
@@ -557,6 +562,7 @@ class NumberedPolynomialTest {
             )
             assertEquals(
                 NumberedPolynomial(
+                    listOf<UInt>() to Rational(0),
                     listOf(3u) to Rational(-8, 9),
                     listOf(0u, 4u) to Rational(-8, 7),
                 ),
@@ -650,6 +656,7 @@ class NumberedPolynomialTest {
             )
             assertEquals(
                 NumberedPolynomial(
+                    listOf<UInt>() to Rational(0),
                     listOf(3u) to Rational(-8, 9),
                     listOf(0u, 4u) to Rational(-8, 7),
                 ),
@@ -816,6 +823,7 @@ class NumberedPolynomialTest {
             )
             assertEquals(
                 NumberedPolynomial(
+                    listOf<UInt>() to Rational(0),
                     listOf(3u) to Rational(-8, 9),
                     listOf(0u, 4u) to Rational(-8, 7),
                 ),

kmath-functions/src/commonTest/kotlin/space/kscience/kmath/test/misc/assertion.kt

@@ -5,6 +5,8 @@
 
 package space.kscience.kmath.test.misc
 
+import space.kscience.kmath.functions.LabeledPolynomial
+import space.kscience.kmath.functions.LabeledRationalFunction
 import space.kscience.kmath.functions.NumberedPolynomial
 import space.kscience.kmath.functions.NumberedRationalFunction
 import kotlin.test.assertEquals
@@ -28,6 +30,18 @@ fun assertEquals(
     message
 )
 
+fun assertEquals(
+    expected: LabeledPolynomial<Double>,
+    actual: LabeledPolynomial<Double>,
+    absoluteTolerance: Double,
+    message: String? = null
+) = assertContentEquals(
+    expected.coefficients,
+    actual.coefficients,
+    absoluteTolerance,
+    message
+)
+
 fun assertEquals(
     expected: NumberedRationalFunction<Double>,
     actual: NumberedRationalFunction<Double>,
@@ -48,6 +62,26 @@ fun assertEquals(
     )
 }
 
+fun assertEquals(
+    expected: LabeledRationalFunction<Double>,
+    actual: LabeledRationalFunction<Double>,
+    absoluteTolerance: Double,
+    message: String? = null
+) {
+    assertEquals(
+        expected.numerator,
+        actual.numerator,
+        absoluteTolerance,
+        message
+    )
+    assertEquals(
+        expected.denominator,
+        actual.denominator,
+        absoluteTolerance,
+        message
+    )
+}
+
 inline fun <reified T : Throwable> assertFailsWithTypeAndMessage(
     expectedMessage: String? = null,
     assertionMessage: String? = null,