From c92e87faf37b3f7fc4346161404f5812c9c42356 Mon Sep 17 00:00:00 2001 From: Satoshi Kataoka Date: Fri, 10 May 2013 18:00:33 +0900 Subject: [PATCH] Add smoothing utils / matrix libs Bug: 8556775 Change-Id: I7e0516b344937b84b7d57cc4e5009b7f88e7dc98 --- .../keyboard/internal/MatrixUtils.java | 166 ++++++++++++++++++ .../keyboard/internal/SmoothingUtils.java | 102 +++++++++++ .../keyboard/internal/MatrixUtilsTests.java | 84 +++++++++ .../internal/SmoothingUtilsTests.java | 45 +++++ 4 files changed, 397 insertions(+) create mode 100644 java/src/com/android/inputmethod/keyboard/internal/MatrixUtils.java create mode 100644 java/src/com/android/inputmethod/keyboard/internal/SmoothingUtils.java create mode 100644 tests/src/com/android/inputmethod/keyboard/internal/MatrixUtilsTests.java create mode 100644 tests/src/com/android/inputmethod/keyboard/internal/SmoothingUtilsTests.java diff --git a/java/src/com/android/inputmethod/keyboard/internal/MatrixUtils.java b/java/src/com/android/inputmethod/keyboard/internal/MatrixUtils.java new file mode 100644 index 000000000..4916a15b5 --- /dev/null +++ b/java/src/com/android/inputmethod/keyboard/internal/MatrixUtils.java @@ -0,0 +1,166 @@ +/* + * 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.inputmethod.keyboard.internal; + +import com.android.inputmethod.annotations.UsedForTesting; + +import android.util.Log; + +import java.util.Arrays; + +/** + * Utilities for matrix operations. Don't instantiate objects inside this class to prevent + * unexpected performance regressions. + */ +@UsedForTesting +public class MatrixUtils { + private static final String TAG = MatrixUtils.class.getSimpleName(); + public static class MatrixOperationFailedException extends Exception { + private static final String TAG = MatrixOperationFailedException.class.getSimpleName(); + private static final long serialVersionUID = 4384485606788583829L; + + public MatrixOperationFailedException(String msg) { + super(msg); + Log.d(TAG, msg); + } + } + + /** + * A utility function to inverse matrix. + * Find a pivot and swap the row of squareMatrix0 and squareMatrix1 + */ + private static void findPivotAndSwapRow(final int row, final float[][] squareMatrix0, + final float[][] squareMatrix1, final int size) { + int ip = row; + float pivot = Math.abs(squareMatrix0[row][row]); + for (int i = row + 1; i < size; ++i) { + if (pivot < Math.abs(squareMatrix0[i][row])) { + ip = i; + pivot = Math.abs(squareMatrix0[i][row]); + } + } + if (ip != row) { + for (int j = 0; j < size; ++j) { + final float temp0 = squareMatrix0[ip][j]; + squareMatrix0[ip][j] = squareMatrix0[row][j]; + squareMatrix0[row][j] = temp0; + final float temp1 = squareMatrix1[ip][j]; + squareMatrix1[ip][j] = squareMatrix1[row][j]; + squareMatrix1[row][j] = temp1; + } + } + } + + /** + * A utility function to inverse matrix. This function calculates answer for each row by + * sweeping method of Gauss Jordan elimination + */ + private static void sweep(final int row, final float[][] squareMatrix0, + final float[][] squareMatrix1, final int size) throws MatrixOperationFailedException { + final float pivot = squareMatrix0[row][row]; + if (pivot == 0) { + throw new MatrixOperationFailedException("Inverse failed. Invalid pivot"); + } + for (int j = 0; j < size; ++j) { + squareMatrix0[row][j] /= pivot; + squareMatrix1[row][j] /= pivot; + } + for (int i = 0; i < size; i++) { + final float sweepTargetValue = squareMatrix0[i][row]; + if (i != row) { + for (int j = row; j < size; ++j) { + squareMatrix0[i][j] -= sweepTargetValue * squareMatrix0[row][j]; + } + for (int j = 0; j < size; ++j) { + squareMatrix1[i][j] -= sweepTargetValue * squareMatrix1[row][j]; + } + } + } + } + + /** + * A function to inverse matrix. + * The inverse matrix of squareMatrix will be output to inverseMatrix. Please notice that + * the value of squareMatrix is modified in this function and can't be resuable. + */ + @UsedForTesting + public static void inverse(final float[][] squareMatrix, + final float[][] inverseMatrix) throws MatrixOperationFailedException { + final int size = squareMatrix.length; + if (squareMatrix[0].length != size || inverseMatrix.length != size + || inverseMatrix[0].length != size) { + throw new MatrixOperationFailedException( + "--- invalid length. column should be 2 times larger than row."); + } + for (int i = 0; i < size; ++i) { + Arrays.fill(inverseMatrix[i], 0.0f); + inverseMatrix[i][i] = 1.0f; + } + for (int i = 0; i < size; ++i) { + findPivotAndSwapRow(i, squareMatrix, inverseMatrix, size); + sweep(i, squareMatrix, inverseMatrix, size); + } + } + + /** + * A matrix operation to multiply m0 and m1. + */ + @UsedForTesting + public static void multiply(final float[][] m0, final float[][] m1, + final float[][] retval) throws MatrixOperationFailedException { + if (m0[0].length != m1.length) { + throw new MatrixOperationFailedException( + "--- invalid length for multiply " + m0[0].length + ", " + m1.length); + } + final int m0h = m0.length; + final int m0w = m0[0].length; + final int m1w = m1[0].length; + if (retval.length != m0h || retval[0].length != m1w) { + throw new MatrixOperationFailedException( + "--- invalid length of retval " + retval.length + ", " + retval[0].length); + } + + for (int i = 0; i < m0h; i++) { + Arrays.fill(retval[i], 0); + for (int j = 0; j < m1w; j++) { + for (int k = 0; k < m0w; k++) { + retval[i][j] += m0[i][k] * m1[k][j]; + } + } + } + } + + /** + * A utility function to dump the specified matrix in a readable way + */ + @UsedForTesting + public static void dump(final String title, final float[][] a) { + final int column = a[0].length; + final int row = a.length; + Log.d(TAG, "Dump matrix: " + title); + Log.d(TAG, "/*---------------------"); + final StringBuilder sb = new StringBuilder(); + for (int i = 0; i < row; ++i) { + sb.setLength(0); + for (int j = 0; j < column; ++j) { + sb.append(String.format("%4f", a[i][j])).append(' '); + } + Log.d(TAG, sb.toString()); + } + Log.d(TAG, "---------------------*/"); + } +} diff --git a/java/src/com/android/inputmethod/keyboard/internal/SmoothingUtils.java b/java/src/com/android/inputmethod/keyboard/internal/SmoothingUtils.java new file mode 100644 index 000000000..e5665bcdd --- /dev/null +++ b/java/src/com/android/inputmethod/keyboard/internal/SmoothingUtils.java @@ -0,0 +1,102 @@ +/* + * 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.inputmethod.keyboard.internal; + +import com.android.inputmethod.annotations.UsedForTesting; +import com.android.inputmethod.keyboard.internal.MatrixUtils.MatrixOperationFailedException; + +import android.util.Log; + +import java.util.Arrays; + +/** + * Utilities to smooth coordinates. Currently, we calculate 3d least squares formula by using + * Lagrangian smoothing + */ +@UsedForTesting +public class SmoothingUtils { + private static final String TAG = SmoothingUtils.class.getSimpleName(); + private static final boolean DEBUG = false; + + private SmoothingUtils() { + // not allowed to instantiate publicly + } + + /** + * Find a most likely 3d least squares formula for specified coordinates. + * "retval" should be a 1x4 size matrix. + */ + @UsedForTesting + public static void get3DParameters(final float[] xs, final float[] ys, + final float[][] retval) throws MatrixOperationFailedException { + final int COEFF_COUNT = 4; // Coefficient count for 3d smoothing + if (retval.length != COEFF_COUNT || retval[0].length != 1) { + Log.d(TAG, "--- invalid length of 3d retval " + retval.length + ", " + + retval[0].length); + return; + } + final int N = xs.length; + // TODO: Never isntantiate the matrix + final float[][] m0 = new float[COEFF_COUNT][COEFF_COUNT]; + final float[][] m0Inv = new float[COEFF_COUNT][COEFF_COUNT]; + final float[][] m1 = new float[COEFF_COUNT][N]; + final float[][] m2 = new float[N][1]; + + // m0 + for (int i = 0; i < COEFF_COUNT; ++i) { + Arrays.fill(m0[i], 0); + for (int j = 0; j < COEFF_COUNT; ++j) { + final int pow = i + j; + for (int k = 0; k < N; ++k) { + m0[i][j] += (float) Math.pow((double) xs[k], pow); + } + } + } + // m0Inv + MatrixUtils.inverse(m0, m0Inv); + if (DEBUG) { + MatrixUtils.dump("m0-1", m0Inv); + } + + // m1 + for (int i = 0; i < COEFF_COUNT; ++i) { + for (int j = 0; j < N; ++j) { + m1[i][j] = (i == 0) ? 1.0f : m1[i - 1][j] * xs[j]; + } + } + + // m2 + for (int i = 0; i < N; ++i) { + m2[i][0] = ys[i]; + } + + final float[][] m0Invxm1 = new float[COEFF_COUNT][N]; + if (DEBUG) { + MatrixUtils.dump("a0", m0Inv); + MatrixUtils.dump("a1", m1); + } + MatrixUtils.multiply(m0Inv, m1, m0Invxm1); + if (DEBUG) { + MatrixUtils.dump("a2", m0Invxm1); + MatrixUtils.dump("a3", m2); + } + MatrixUtils.multiply(m0Invxm1, m2, retval); + if (DEBUG) { + MatrixUtils.dump("result", retval); + } + } +} diff --git a/tests/src/com/android/inputmethod/keyboard/internal/MatrixUtilsTests.java b/tests/src/com/android/inputmethod/keyboard/internal/MatrixUtilsTests.java new file mode 100644 index 000000000..e2a11ab99 --- /dev/null +++ b/tests/src/com/android/inputmethod/keyboard/internal/MatrixUtilsTests.java @@ -0,0 +1,84 @@ +/* + * 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.inputmethod.keyboard.internal; + +import com.android.inputmethod.keyboard.internal.MatrixUtils.MatrixOperationFailedException; + +import android.test.AndroidTestCase; +import android.test.suitebuilder.annotation.SmallTest; + +@SmallTest +public class MatrixUtilsTests extends AndroidTestCase { + // "run tests" -c com.android.inputmethod.keyboard.internal.MatrixUtilsTests + private static final boolean DEBUG = false; + private static final float EPSILON = 0.00001f; + + private static void assertEqualsFloat(float f0, float f1) { + assertEqualsFloat(f0, f1, EPSILON); + } + + /* package */ static void assertEqualsFloat(float f0, float f1, float error) { + assertTrue(Math.abs(f0 - f1) < error); + } + + public void testMulti() { + final float[][] matrixA = {{1, 2}, {3, 4}}; + final float[][] matrixB = {{5, 6}, {7, 8}}; + final float[][] retval = new float[2][2]; + try { + MatrixUtils.multiply(matrixA, matrixB, retval); + } catch (MatrixOperationFailedException e) { + assertTrue(false); + } + if (DEBUG) { + MatrixUtils.dump("multi", retval); + } + assertEqualsFloat(retval[0][0], 19); + assertEqualsFloat(retval[0][1], 22); + assertEqualsFloat(retval[1][0], 43); + assertEqualsFloat(retval[1][1], 50); + } + + public void testInverse() { + final int N = 4; + final float[][] matrix = + {{1, 2, 3, 4}, {4, 0, 5, 6}, {6, 4, 2, 0}, {6, 4, 2, 1}}; + final float[][] inverse = new float[N][N]; + final float[][] tempMatrix = new float[N][N]; + for (int i = 0; i < N; ++i) { + for (int j = 0; j < N; ++j) { + tempMatrix[i][j] = matrix[i][j]; + } + } + final float[][] retval = new float[N][N]; + try { + MatrixUtils.inverse(tempMatrix, inverse); + } catch (MatrixOperationFailedException e) { + assertTrue(false); + } + try { + MatrixUtils.multiply(matrix, inverse, retval); + } catch (MatrixOperationFailedException e) { + assertTrue(false); + } + for (int i = 0; i < N; ++i) { + for (int j = 0; j < N; ++j) { + assertEqualsFloat(((i == j) ? 1.0f : 0.0f), retval[i][j]); + } + } + } +} diff --git a/tests/src/com/android/inputmethod/keyboard/internal/SmoothingUtilsTests.java b/tests/src/com/android/inputmethod/keyboard/internal/SmoothingUtilsTests.java new file mode 100644 index 000000000..293741af2 --- /dev/null +++ b/tests/src/com/android/inputmethod/keyboard/internal/SmoothingUtilsTests.java @@ -0,0 +1,45 @@ +/* + * 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.inputmethod.keyboard.internal; + +import com.android.inputmethod.keyboard.internal.MatrixUtils.MatrixOperationFailedException; + +import android.test.AndroidTestCase; +import android.test.suitebuilder.annotation.SmallTest; + +@SmallTest +public class SmoothingUtilsTests extends AndroidTestCase { + // "run tests" -c com.android.inputmethod.keyboard.internal.SmoothingUtilsTests + private static final boolean DEBUG = false; + + public void testGet3DParamaters() { + final float[] xs = new float[] {0, 1, 2, 3, 4}; + final float[] ys = new float[] {1, 4, 15, 40, 85}; // y = x^3 + x^2 + x + 1 + final float[][] retval = new float[4][1]; + try { + SmoothingUtils.get3DParameters(xs, ys, retval); + if (DEBUG) { + MatrixUtils.dump("3d", retval); + } + for (int i = 0; i < 4; ++i) { + MatrixUtilsTests.assertEqualsFloat(retval[i][0], 1.0f, 0.001f); + } + } catch (MatrixOperationFailedException e) { + assertTrue(false); + } + } +}