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

@@ -211,7 +211,7 @@ public class LabeledPolynomialSpace<C, A : Ring<C>>(
         else LabeledPolynomial(
             coefficients
                 .applyAndRemoveZeros {
-                    mapValues { (_, c) -> c * other }
+                    for (degs in keys) this[degs] = this[degs]!! * other
                 }
         )
 
@@ -265,7 +265,7 @@ public class LabeledPolynomialSpace<C, A : Ring<C>>(
         else LabeledPolynomial(
             other.coefficients
                 .applyAndRemoveZeros {
-                    mapValues { (_, c) -> this@times * c }
+                    for (degs in keys) this[degs] = this@times * this[degs]!!
                 }
         )
 
@@ -361,7 +361,7 @@ public class LabeledPolynomialSpace<C, A : Ring<C>>(
         else LabeledPolynomial<C>(
             other.coefficients
                 .applyAndRemoveZeros {
-                    mapValues { (_, c) -> this@times * c }
+                    for (degs in keys) this[degs] = this@times * this[degs]!!
                 }
         )
 
@@ -413,7 +413,7 @@ public class LabeledPolynomialSpace<C, A : Ring<C>>(
         else LabeledPolynomial<C>(
             coefficients
                 .applyAndRemoveZeros {
-                    mapValues { (_, c) -> c * other }
+                    for (degs in keys) this[degs] = this[degs]!! * other
                 }
         )
 
@@ -525,22 +525,20 @@ public class LabeledPolynomialSpace<C, A : Ring<C>>(
      */
     override operator fun LabeledPolynomial<C>.plus(other: LabeledPolynomial<C>): LabeledPolynomial<C> =
         LabeledPolynomial<C>(
-            coefficients
-                .applyAndRemoveZeros {
-                    other.coefficients
-                        .mapValuesTo(this) { (key, value) -> if (key in this) this[key]!! + value else value }
-                }
+            buildCoefficients(coefficients.size + other.coefficients.size) {
+                other.coefficients.mapValuesTo(this) { it.value }
+                other.coefficients.mapValuesTo(this) { (key, value) -> if (key in this) this[key]!! + value else value }
+            }
         )
     /**
      * Returns difference of the polynomials.
      */
     override operator fun LabeledPolynomial<C>.minus(other: LabeledPolynomial<C>): LabeledPolynomial<C> =
         LabeledPolynomial<C>(
-            coefficients
-                .applyAndRemoveZeros {
-                    other.coefficients
-                        .mapValuesTo(this) { (key, value) -> if (key in this) this[key]!! - value else -value }
-                }
+            buildCoefficients(coefficients.size + other.coefficients.size) {
+                other.coefficients.mapValuesTo(this) { it.value }
+                other.coefficients.mapValuesTo(this) { (key, value) -> if (key in this) this[key]!! - value else -value }
+            }
         )
     /**
      * Returns product of the polynomials.

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

@@ -163,7 +163,7 @@ public open class NumberedPolynomialSpace<C, A : Ring<C>>(
         else NumberedPolynomial<C>(
             coefficients
                 .applyAndRemoveZeros {
-                    mapValues { (_, c) -> c * other }
+                    for (degs in keys) this[degs] = this[degs]!! * other
                 }
         )
 
@@ -217,7 +217,7 @@ public open class NumberedPolynomialSpace<C, A : Ring<C>>(
         else NumberedPolynomial(
             other.coefficients
                 .applyAndRemoveZeros {
-                    mapValues { (_, c) -> this@times * c }
+                    for (degs in keys) this[degs] = this@times * this[degs]!!
                 }
         )
 
@@ -269,7 +269,7 @@ public open class NumberedPolynomialSpace<C, A : Ring<C>>(
         else NumberedPolynomial<C>(
             other.coefficients
                 .applyAndRemoveZeros {
-                    mapValues { (_, c) -> this@times * c }
+                    for (degs in keys) this[degs] = this@times * this[degs]!!
                 }
         )
 
@@ -319,7 +319,7 @@ public open class NumberedPolynomialSpace<C, A : Ring<C>>(
         else NumberedPolynomial<C>(
             coefficients
                 .applyAndRemoveZeros {
-                    mapValues { (_, c) -> c * other }
+                    for (degs in keys) this[degs] = this[degs]!! * other
                 }
         )
 
@@ -335,22 +335,20 @@ public open class NumberedPolynomialSpace<C, A : Ring<C>>(
      */
     override operator fun NumberedPolynomial<C>.plus(other: NumberedPolynomial<C>): NumberedPolynomial<C> =
         NumberedPolynomial<C>(
-            coefficients
-                .applyAndRemoveZeros {
-                    other.coefficients
-                        .mapValuesTo(this) { (key, value) -> if (key in this) this[key]!! + value else value }
-                }
+            buildCoefficients(coefficients.size + other.coefficients.size) {
+                other.coefficients.mapValuesTo(this) { it.value }
+                other.coefficients.mapValuesTo(this) { (key, value) -> if (key in this) this[key]!! + value else value }
+            }
         )
     /**
      * Returns difference of the polynomials.
      */
     override operator fun NumberedPolynomial<C>.minus(other: NumberedPolynomial<C>): NumberedPolynomial<C> =
         NumberedPolynomial<C>(
-            coefficients
-                .applyAndRemoveZeros {
-                    other.coefficients
-                        .mapValuesTo(this) { (key, value) -> if (key in this) this[key]!! - value else -value }
-                }
+            buildCoefficients(coefficients.size + other.coefficients.size) {
+                other.coefficients.mapValuesTo(this) { it.value }
+                other.coefficients.mapValuesTo(this) { (key, value) -> if (key in this) this[key]!! - value else -value }
+            }
         )
     /**
      * Returns product of the polynomials.

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

@@ -129,7 +129,7 @@ public open class PolynomialSpace<C, A : Ring<C>>(
         else Polynomial(
             coefficients
                 .applyAndRemoveZeros {
-                    map { it * other }
+                    for (deg in indices) this[deg] = this[deg] * other
                 }
         )
 
@@ -189,7 +189,7 @@ public open class PolynomialSpace<C, A : Ring<C>>(
         else Polynomial(
             other.coefficients
                 .applyAndRemoveZeros {
-                    map { it * this@times }
+                    for (deg in indices) this[deg] = this@times * this[deg]
                 }
         )
 
@@ -245,7 +245,7 @@ public open class PolynomialSpace<C, A : Ring<C>>(
         else Polynomial(
             other.coefficients
                 .applyAndRemoveZeros {
-                    map { it * this@times }
+                    for (deg in indices) this[deg] = this@times * this[deg]
                 }
         )
 
@@ -299,7 +299,7 @@ public open class PolynomialSpace<C, A : Ring<C>>(
         else Polynomial(
             coefficients
                 .applyAndRemoveZeros {
-                    map { it * other }
+                    for (deg in indices) this[deg] = this[deg] * other
                 }
         )
 
@@ -452,12 +452,14 @@ public open class PolynomialSpace<C, A : Ring<C>>(
     }
     internal inline fun List<C>.applyAndRemoveZeros(block: MutableList<C>.() -> Unit) : List<C> =
         toMutableList().applyAndRemoveZeros(block)
+    @Suppress("FunctionName")
     internal inline fun MutableCoefficients(size: Int, init: (index: Int) -> C): MutableList<C> {
         val list = ArrayList<C>(size)
         repeat(size) { index -> list.add(init(index)) }
         with(list) { while (elementAt(lastIndex).isZero()) removeAt(lastIndex) }
         return list
     }
+    @Suppress("FunctionName")
     internal inline fun Coefficients(size: Int, init: (index: Int) -> C): List<C> = MutableCoefficients(size, init)
     @OptIn(ExperimentalTypeInference::class)
     internal inline fun buildCoefficients(@BuilderInference builderAction: MutableList<C>.() -> Unit): List<C> {

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

@@ -96,7 +96,6 @@ internal inline fun <C> multiplyAddingTo(
             target[d] += multiplicand[k] * multiplier[d - k]
 }
 
-// TODO: May be apply Horner's method too?
 /**
  * Evaluates the value of the given double polynomial for given double argument.
  */