1 files changed, 82 insertions, 0 deletions
diff --git a/src/main/java/org/apache/commons/math3/complex/ComplexUtils.java b/src/main/java/org/apache/commons/math3/complex/ComplexUtils.java
new file mode 100644
index 0000000..6fca857
--- /dev/null
+++ b/src/main/java/org/apache/commons/math3/complex/ComplexUtils.java
@@ -0,0 +1,82 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.commons.math3.complex;
+
+import org.apache.commons.math3.exception.MathIllegalArgumentException;
+import org.apache.commons.math3.exception.util.LocalizedFormats;
+import org.apache.commons.math3.util.FastMath;
+
+/**
+ * Static implementations of common {@link org.apache.commons.math3.complex.Complex} utilities
+ * functions.
+ */
+public class ComplexUtils {
+
+    /** Default constructor. */
+    private ComplexUtils() {}
+
+    /**
+     * Creates a complex number from the given polar representation.
+     *
+     * <p>The value returned is <code>r&middot;e<sup>i&middot;theta</sup></code>, computed as <code>
+     * r&middot;cos(theta) + r&middot;sin(theta)i</code>
+     *
+     * <p>If either <code>r</code> or <code>theta</code> is NaN, or <code>theta</code> is infinite,
+     * {@link Complex#NaN} is returned.
+     *
+     * <p>If <code>r</code> is infinite and <code>theta</code> is finite, infinite or NaN values may
+     * be returned in parts of the result, following the rules for double arithmetic.
+     *
+     * <pre>
+     * Examples:
+     * <code>
+     * polar2Complex(INFINITY, &pi;/4) = INFINITY + INFINITY i
+     * polar2Complex(INFINITY, 0) = INFINITY + NaN i
+     * polar2Complex(INFINITY, -&pi;/4) = INFINITY - INFINITY i
+     * polar2Complex(INFINITY, 5&pi;/4) = -INFINITY - INFINITY i </code></pre>
+     *
+     * @param r the modulus of the complex number to create
+     * @param theta the argument of the complex number to create
+     * @return <code>r&middot;e<sup>i&middot;theta</sup></code>
+     * @throws MathIllegalArgumentException if {@code r} is negative.
+     * @since 1.1
+     */
+    public static Complex polar2Complex(double r, double theta)
+            throws MathIllegalArgumentException {
+        if (r < 0) {
+            throw new MathIllegalArgumentException(LocalizedFormats.NEGATIVE_COMPLEX_MODULE, r);
+        }
+        return new Complex(r * FastMath.cos(theta), r * FastMath.sin(theta));
+    }
+
+    /**
+     * Convert an array of primitive doubles to an array of {@code Complex} objects.
+     *
+     * @param real Array of numbers to be converted to their {@code Complex} equivalent.
+     * @return an array of {@code Complex} objects.
+     * @since 3.1
+     */
+    public static Complex[] convertToComplex(double[] real) {
+        final Complex c[] = new Complex[real.length];
+        for (int i = 0; i < real.length; i++) {
+            c[i] = new Complex(real[i], 0);
+        }
+
+        return c;
+    }
+}