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+/*
+ * 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.ode.nonstiff;
+
+
+/**
+ * This class implements a simple Euler integrator for Ordinary
+ * Differential Equations.
+ *
+ * <p>The Euler algorithm is the simplest one that can be used to
+ * integrate ordinary differential equations. It is a simple inversion
+ * of the forward difference expression :
+ * <code>f'=(f(t+h)-f(t))/h</code> which leads to
+ * <code>f(t+h)=f(t)+hf'</code>. The interpolation scheme used for
+ * dense output is the linear scheme already used for integration.</p>
+ *
+ * <p>This algorithm looks cheap because it needs only one function
+ * evaluation per step. However, as it uses linear estimates, it needs
+ * very small steps to achieve high accuracy, and small steps lead to
+ * numerical errors and instabilities.</p>
+ *
+ * <p>This algorithm is almost never used and has been included in
+ * this package only as a comparison reference for more useful
+ * integrators.</p>
+ *
+ * @see MidpointIntegrator
+ * @see ClassicalRungeKuttaIntegrator
+ * @see GillIntegrator
+ * @see ThreeEighthesIntegrator
+ * @see LutherIntegrator
+ * @since 1.2
+ */
+
+public class EulerIntegrator extends RungeKuttaIntegrator {
+
+  /** Time steps Butcher array. */
+  private static final double[] STATIC_C = {
+  };
+
+  /** Internal weights Butcher array. */
+  private static final double[][] STATIC_A = {
+  };
+
+  /** Propagation weights Butcher array. */
+  private static final double[] STATIC_B = {
+    1.0
+  };
+
+  /** Simple constructor.
+   * Build an Euler integrator with the given step.
+   * @param step integration step
+   */
+  public EulerIntegrator(final double step) {
+    super("Euler", STATIC_C, STATIC_A, STATIC_B, new EulerStepInterpolator(), step);
+  }
+
+}