https://github.com/crowlogic/arb4j/issues/253

crowlogic · Nov 28, 2024 · 627e42d · 627e42d
1 parent f3b7c86
commit 627e42d
Show file tree

Hide file tree

Showing 3 changed files with 12 additions and 8 deletions.
diff --git a/src/main/java/arb/expressions/nodes/DerivativeNode.java b/src/main/java/arb/expressions/nodes/DerivativeNode.java
@@ -75,7 +75,7 @@ public class DerivativeNode<D, R, F extends Function<? extends D, ? extends R>>
   @Override
   public String toString()
   {
-    return String.format("DerivativeNode[operand=%s, variable=%s, derivative=%s]", operand, variable, derivative);
+    return derivative.toString();
   }
 
   public Node<D, R, F>         operand;

diff --git a/src/main/java/arb/expressions/nodes/binary/AdditionNode.java b/src/main/java/arb/expressions/nodes/binary/AdditionNode.java
@@ -43,9 +43,7 @@ public boolean isCommutative()
          Node<E, S, G>
          spliceInto(Expression<E, S, G> newExpression)
   {
-    return new AdditionNode<E, S, G>(newExpression,
-                                     left.spliceInto(newExpression),
-                                     right.spliceInto(newExpression));
+    return left.spliceInto(newExpression).add(right.spliceInto(newExpression));
   }
 
   @Override

diff --git a/src/test/java/arb/expressions/ExpressionTest.java b/src/test/java/arb/expressions/ExpressionTest.java
@@ -5,6 +5,7 @@
 import arb.RationalFunction;
 import arb.Real;
 import arb.RealConstants;
+import arb.RoundingMode;
 import arb.documentation.BusinessSourceLicenseVersionOnePointOne;
 import arb.documentation.TheArb4jLibrary;
 import arb.exceptions.CompilerException;
@@ -121,11 +122,16 @@ public void testDerivativeToo()
 
   public void testRealPolynomialDerivative()
   {
-    var context = new Context(Real.named("a"),
-                              Real.named("b"),
-                              Real.named("c"));
+    var context = new Context(Real.named("a").set(2),
+                              Real.named("b").set(4),
+                              Real.named("c").set(6));
     var x       = RealPolynomialNullaryFunction.express("x->∂a*x+b*x²+c*x³/∂x", context);
-    assertEquals("a+2*b*x+3*c*x^2", x.typeset());
+    assertEquals("x➔∂a*x+b*x²+c*x³/∂x", x.toString());
+    var poly = x.evaluate(128);
+    assertEquals("18*x² + 8*x + 2", poly.toString());
+    var y = poly.evaluate(new Real("2.3", 128), 1, 128, new Real() );
+    y.printPrecision = false;
+    assertEquals( "115.62", y.toString() );   
   }
 
   /**