Author: celestin Date: Fri Dec 9 06:45:09 2011 New Revision: 1212260 URL: http://svn.apache.org/viewvc?rev=1212260&view=rev Log: Cosmetic changes to transform.FastFourierTransformer (MATH-677).
Modified: commons/proper/math/trunk/src/main/java/org/apache/commons/math/transform/FastFourierTransformer.java Modified: commons/proper/math/trunk/src/main/java/org/apache/commons/math/transform/FastFourierTransformer.java URL: http://svn.apache.org/viewvc/commons/proper/math/trunk/src/main/java/org/apache/commons/math/transform/FastFourierTransformer.java?rev=1212260&r1=1212259&r2=1212260&view=diff ============================================================================== --- commons/proper/math/trunk/src/main/java/org/apache/commons/math/transform/FastFourierTransformer.java (original) +++ commons/proper/math/trunk/src/main/java/org/apache/commons/math/transform/FastFourierTransformer.java Fri Dec 9 06:45:09 2011 @@ -52,9 +52,8 @@ public class FastFourierTransformer impl /** Serializable version identifier. */ static final long serialVersionUID = 5138259215438106000L; - /** - * {@code true} if the orthogonal version of the FFT should be used. + * {@code true} if the unitary version of the DFT should be used. * * @see #create() * @see #createUnitary() @@ -64,19 +63,12 @@ public class FastFourierTransformer impl /** The roots of unity. */ private RootsOfUnity roots = new RootsOfUnity(); - /** Construct a default transformer. */ - private FastFourierTransformer() { - super(); - this.unitary = false; - } - /** * Creates a new instance of this class, with various normalization * conventions. * - * @param unitary {@code false} if the direct Fourier transform is - * <em>not</em> to be scaled, {@code true} if it is to be scaled so as to - * make the transform unitary. + * @param unitary {@code false} if the DFT is <em>not</em> to be scaled, + * {@code true} if it is to be scaled so as to make the transform unitary. * @see #create() * @see #createUnitary() */ @@ -88,17 +80,18 @@ public class FastFourierTransformer impl * <p> * Returns a new instance of this class. The returned transformer uses the * normalizing conventions described below. - * </p> * <ul> * <li>Forward transform: * y<sub>n</sub> = ∑<sub>k=0</sub><sup>N-1</sup> * x<sub>k</sub> exp(-2πi n k / N),</li> * <li>Inverse transform: * x<sub>k</sub> = N<sup>-1</sup> ∑<sub>n=0</sub><sup>N-1</sup> - * y<sub>n</sub> exp(2πi n k / N).</li> + * y<sub>n</sub> exp(2πi n k / N),</li> * </ul> + * where N is the size of the data sample. + * </p> * - * @return a new FFT transformer, with "standard" normalizing conventions + * @return a new DFT transformer, with "standard" normalizing conventions */ public static FastFourierTransformer create() { return new FastFourierTransformer(false); @@ -116,7 +109,7 @@ public class FastFourierTransformer impl * x<sub>k</sub> = N<sup>-1/2</sup> ∑<sub>n=0</sub><sup>N-1</sup> * y<sub>n</sub> exp(2πi n k / N),</li> * </ul> - * which make the transform unitary. + * which make the transform unitary. N is the size of the data sample. * </p> * * @return a new FFT transformer, with unitary normalizing conventions