1 files changed, 111 insertions, 0 deletions
diff --git a/src/main/java/org/apache/commons/math3/optimization/fitting/PolynomialFitter.java b/src/main/java/org/apache/commons/math3/optimization/fitting/PolynomialFitter.java
new file mode 100644
index 0000000..dbefcc2
--- /dev/null
+++ b/src/main/java/org/apache/commons/math3/optimization/fitting/PolynomialFitter.java
@@ -0,0 +1,111 @@
+/*
+ * 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.optimization.fitting;
+
+import org.apache.commons.math3.analysis.polynomials.PolynomialFunction;
+import org.apache.commons.math3.optimization.DifferentiableMultivariateVectorOptimizer;
+
+/**
+ * Polynomial fitting is a very simple case of {@link CurveFitter curve fitting}.
+ * The estimated coefficients are the polynomial coefficients (see the
+ * {@link #fit(double[]) fit} method).
+ *
+ * @deprecated As of 3.1 (to be removed in 4.0).
+ * @since 2.0
+ */
+@Deprecated
+public class PolynomialFitter extends CurveFitter<PolynomialFunction.Parametric> {
+    /** Polynomial degree.
+     * @deprecated
+     */
+    @Deprecated
+    private final int degree;
+
+    /**
+     * Simple constructor.
+     * <p>The polynomial fitter built this way are complete polynomials,
+     * ie. a n-degree polynomial has n+1 coefficients.</p>
+     *
+     * @param degree Maximal degree of the polynomial.
+     * @param optimizer Optimizer to use for the fitting.
+     * @deprecated Since 3.1 (to be removed in 4.0). Please use
+     * {@link #PolynomialFitter(DifferentiableMultivariateVectorOptimizer)} instead.
+     */
+    @Deprecated
+    public PolynomialFitter(int degree, final DifferentiableMultivariateVectorOptimizer optimizer) {
+        super(optimizer);
+        this.degree = degree;
+    }
+
+    /**
+     * Simple constructor.
+     *
+     * @param optimizer Optimizer to use for the fitting.
+     * @since 3.1
+     */
+    public PolynomialFitter(DifferentiableMultivariateVectorOptimizer optimizer) {
+        super(optimizer);
+        degree = -1; // To avoid compilation error until the instance variable is removed.
+    }
+
+    /**
+     * Get the polynomial fitting the weighted (x, y) points.
+     *
+     * @return the coefficients of the polynomial that best fits the observed points.
+     * @throws org.apache.commons.math3.exception.ConvergenceException
+     * if the algorithm failed to converge.
+     * @deprecated Since 3.1 (to be removed in 4.0). Please use {@link #fit(double[])} instead.
+     */
+    @Deprecated
+    public double[] fit() {
+        return fit(new PolynomialFunction.Parametric(), new double[degree + 1]);
+    }
+
+    /**
+     * Get the coefficients of the polynomial fitting the weighted data points.
+     * The degree of the fitting polynomial is {@code guess.length - 1}.
+     *
+     * @param guess First guess for the coefficients. They must be sorted in
+     * increasing order of the polynomial's degree.
+     * @param maxEval Maximum number of evaluations of the polynomial.
+     * @return the coefficients of the polynomial that best fits the observed points.
+     * @throws org.apache.commons.math3.exception.TooManyEvaluationsException if
+     * the number of evaluations exceeds {@code maxEval}.
+     * @throws org.apache.commons.math3.exception.ConvergenceException
+     * if the algorithm failed to converge.
+     * @since 3.1
+     */
+    public double[] fit(int maxEval, double[] guess) {
+        return fit(maxEval, new PolynomialFunction.Parametric(), guess);
+    }
+
+    /**
+     * Get the coefficients of the polynomial fitting the weighted data points.
+     * The degree of the fitting polynomial is {@code guess.length - 1}.
+     *
+     * @param guess First guess for the coefficients. They must be sorted in
+     * increasing order of the polynomial's degree.
+     * @return the coefficients of the polynomial that best fits the observed points.
+     * @throws org.apache.commons.math3.exception.ConvergenceException
+     * if the algorithm failed to converge.
+     * @since 3.1
+     */
+    public double[] fit(double[] guess) {
+        return fit(new PolynomialFunction.Parametric(), guess);
+    }
+}