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Diffstat (limited to 'src/com/android/gallery3d/filtershow/tools/MatrixFit.java')
-rw-r--r-- | src/com/android/gallery3d/filtershow/tools/MatrixFit.java | 200 |
1 files changed, 0 insertions, 200 deletions
diff --git a/src/com/android/gallery3d/filtershow/tools/MatrixFit.java b/src/com/android/gallery3d/filtershow/tools/MatrixFit.java deleted file mode 100644 index 3b815673c..000000000 --- a/src/com/android/gallery3d/filtershow/tools/MatrixFit.java +++ /dev/null @@ -1,200 +0,0 @@ -/* - * Copyright (C) 2013 The Android Open Source Project - * - * Licensed 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 com.android.gallery3d.filtershow.tools; - -import android.util.Log; - -public class MatrixFit { - // Simple implementation of a matrix fit in N dimensions. - - private static final String LOGTAG = "MatrixFit"; - - private double[][] mMatrix; - private int mDimension; - private boolean mValid = false; - private static double sEPS = 1.0f/10000000000.0f; - - public MatrixFit(double[][] from, double[][] to) { - mValid = fit(from, to); - } - - public int getDimension() { - return mDimension; - } - - public boolean isValid() { - return mValid; - } - - public double[][] getMatrix() { - return mMatrix; - } - - public boolean fit(double[][] from, double[][] to) { - if ((from.length != to.length) || (from.length < 1)) { - Log.e(LOGTAG, "from and to must be of same size"); - return false; - } - - mDimension = from[0].length; - mMatrix = new double[mDimension +1][mDimension + mDimension +1]; - - if (from.length < mDimension) { - Log.e(LOGTAG, "Too few points => under-determined system"); - return false; - } - - double[][] q = new double[from.length][mDimension]; - for (int i = 0; i < from.length; i++) { - for (int j = 0; j < mDimension; j++) { - q[i][j] = from[i][j]; - } - } - - double[][] p = new double[to.length][mDimension]; - for (int i = 0; i < to.length; i++) { - for (int j = 0; j < mDimension; j++) { - p[i][j] = to[i][j]; - } - } - - // Make an empty (dim) x (dim + 1) matrix and fill it - double[][] c = new double[mDimension+1][mDimension]; - for (int j = 0; j < mDimension; j++) { - for (int k = 0; k < mDimension + 1; k++) { - for (int i = 0; i < q.length; i++) { - double qt = 1; - if (k < mDimension) { - qt = q[i][k]; - } - c[k][j] += qt * p[i][j]; - } - } - } - - // Make an empty (dim+1) x (dim+1) matrix and fill it - double[][] Q = new double[mDimension+1][mDimension+1]; - for (int qi = 0; qi < q.length; qi++) { - double[] qt = new double[mDimension + 1]; - for (int i = 0; i < mDimension; i++) { - qt[i] = q[qi][i]; - } - qt[mDimension] = 1; - for (int i = 0; i < mDimension + 1; i++) { - for (int j = 0; j < mDimension + 1; j++) { - Q[i][j] += qt[i] * qt[j]; - } - } - } - - // Use a gaussian elimination to solve the linear system - for (int i = 0; i < mDimension + 1; i++) { - for (int j = 0; j < mDimension + 1; j++) { - mMatrix[i][j] = Q[i][j]; - } - for (int j = 0; j < mDimension; j++) { - mMatrix[i][mDimension + 1 + j] = c[i][j]; - } - } - if (!gaussianElimination(mMatrix)) { - return false; - } - return true; - } - - public double[] apply(double[] point) { - if (mDimension != point.length) { - return null; - } - double[] res = new double[mDimension]; - for (int j = 0; j < mDimension; j++) { - for (int i = 0; i < mDimension; i++) { - res[j] += point[i] * mMatrix[i][j+ mDimension +1]; - } - res[j] += mMatrix[mDimension][j+ mDimension +1]; - } - return res; - } - - public void printEquation() { - for (int j = 0; j < mDimension; j++) { - String str = "x" + j + "' = "; - for (int i = 0; i < mDimension; i++) { - str += "x" + i + " * " + mMatrix[i][j+mDimension+1] + " + "; - } - str += mMatrix[mDimension][j+mDimension+1]; - Log.v(LOGTAG, str); - } - } - - private void printMatrix(String name, double[][] matrix) { - Log.v(LOGTAG, "name: " + name); - for (int i = 0; i < matrix.length; i++) { - String str = ""; - for (int j = 0; j < matrix[0].length; j++) { - str += "" + matrix[i][j] + " "; - } - Log.v(LOGTAG, str); - } - } - - /* - * Transforms the given matrix into a row echelon matrix - */ - private boolean gaussianElimination(double[][] m) { - int h = m.length; - int w = m[0].length; - - for (int y = 0; y < h; y++) { - int maxrow = y; - for (int y2 = y + 1; y2 < h; y2++) { // Find max pivot - if (Math.abs(m[y2][y]) > Math.abs(m[maxrow][y])) { - maxrow = y2; - } - } - // swap - for (int i = 0; i < mDimension; i++) { - double t = m[y][i]; - m[y][i] = m[maxrow][i]; - m[maxrow][i] = t; - } - - if (Math.abs(m[y][y]) <= sEPS) { // Singular Matrix - return false; - } - for (int y2 = y + 1; y2 < h; y2++) { // Eliminate column y - double c = m[y2][y] / m[y][y]; - for (int x = y; x < w; x++) { - m[y2][x] -= m[y][x] * c; - } - } - } - for (int y = h -1; y > -1; y--) { // Back substitution - double c = m[y][y]; - for (int y2 = 0; y2 < y; y2++) { - for (int x = w - 1; x > y - 1; x--) { - m[y2][x] -= m[y][x] * m[y2][y] / c; - } - } - m[y][y] /= c; - for (int x = h; x < w; x++) { // Normalize row y - m[y][x] /= c; - } - } - return true; - } -} |