1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 package org.apache.commons.math.linear; 18 19 import org.apache.commons.math.Field; 20 import org.apache.commons.math.FieldElement; 21 22 /** 23 * Interface defining a field-valued vector with basic algebraic operations. 24 * <p> 25 * vector element indexing is 0-based -- e.g., <code>getEntry(0)</code> 26 * returns the first element of the vector. 27 * </p> 28 * <p> 29 * The various <code>mapXxx</code> and <code>mapXxxToSelf</code> methods operate 30 * on vectors element-wise, i.e. they perform the same operation (adding a scalar, 31 * applying a function ...) on each element in turn. The <code>mapXxx</code> 32 * versions create a new vector to hold the result and do not change the instance. 33 * The <code>mapXxxToSelf</code> versions use the instance itself to store the 34 * results, so the instance is changed by these methods. In both cases, the result 35 * vector is returned by the methods, this allows to use the <i>fluent API</i> 36 * style, like this: 37 * </p> 38 * <pre> 39 * RealVector result = v.mapAddToSelf(3.0).mapTanToSelf().mapSquareToSelf(); 40 * </pre> 41 * 42 * @param <T> the type of the field elements 43 * @version $Revision: 780674 $ $Date: 2009-06-01 11:10:55 -0400 (Mon, 01 Jun 2009) $ 44 * @since 2.0 45 */ 46 public interface FieldVector<T extends FieldElement<T>> { 47 48 /** 49 * Get the type of field elements of the vector. 50 * @return type of field elements of the vector 51 */ 52 Field<T> getField(); 53 54 /** 55 * Returns a (deep) copy of this. 56 * @return vector copy 57 */ 58 FieldVector<T> copy(); 59 60 /** 61 * Compute the sum of this and v. 62 * @param v vector to be added 63 * @return this + v 64 * @throws IllegalArgumentException if v is not the same size as this 65 */ 66 FieldVector<T> add(FieldVector<T> v) 67 throws IllegalArgumentException; 68 69 /** 70 * Compute the sum of this and v. 71 * @param v vector to be added 72 * @return this + v 73 * @throws IllegalArgumentException if v is not the same size as this 74 */ 75 FieldVector<T> add(T[] v) 76 throws IllegalArgumentException; 77 78 /** 79 * Compute this minus v. 80 * @param v vector to be subtracted 81 * @return this + v 82 * @throws IllegalArgumentException if v is not the same size as this 83 */ 84 FieldVector<T> subtract(FieldVector<T> v) 85 throws IllegalArgumentException; 86 87 /** 88 * Compute this minus v. 89 * @param v vector to be subtracted 90 * @return this + v 91 * @throws IllegalArgumentException if v is not the same size as this 92 */ 93 FieldVector<T> subtract(T[] v) 94 throws IllegalArgumentException; 95 96 /** 97 * Map an addition operation to each entry. 98 * @param d value to be added to each entry 99 * @return this + d 100 */ 101 FieldVector<T> mapAdd(T d); 102 103 /** 104 * Map an addition operation to each entry. 105 * <p>The instance <strong>is</strong> changed by this method.</p> 106 * @param d value to be added to each entry 107 * @return for convenience, return this 108 */ 109 FieldVector<T> mapAddToSelf(T d); 110 111 /** 112 * Map a subtraction operation to each entry. 113 * @param d value to be subtracted to each entry 114 * @return this - d 115 */ 116 FieldVector<T> mapSubtract(T d); 117 118 /** 119 * Map a subtraction operation to each entry. 120 * <p>The instance <strong>is</strong> changed by this method.</p> 121 * @param d value to be subtracted to each entry 122 * @return for convenience, return this 123 */ 124 FieldVector<T> mapSubtractToSelf(T d); 125 126 /** 127 * Map a multiplication operation to each entry. 128 * @param d value to multiply all entries by 129 * @return this * d 130 */ 131 FieldVector<T> mapMultiply(T d); 132 133 /** 134 * Map a multiplication operation to each entry. 135 * <p>The instance <strong>is</strong> changed by this method.</p> 136 * @param d value to multiply all entries by 137 * @return for convenience, return this 138 */ 139 FieldVector<T> mapMultiplyToSelf(T d); 140 141 /** 142 * Map a division operation to each entry. 143 * @param d value to divide all entries by 144 * @return this / d 145 */ 146 FieldVector<T> mapDivide(T d); 147 148 /** 149 * Map a division operation to each entry. 150 * <p>The instance <strong>is</strong> changed by this method.</p> 151 * @param d value to divide all entries by 152 * @return for convenience, return this 153 */ 154 FieldVector<T> mapDivideToSelf(T d); 155 156 /** 157 * Map the 1/x function to each entry. 158 * @return a vector containing the result of applying the function to each entry 159 */ 160 FieldVector<T> mapInv(); 161 162 /** 163 * Map the 1/x function to each entry. 164 * <p>The instance <strong>is</strong> changed by this method.</p> 165 * @return for convenience, return this 166 */ 167 FieldVector<T> mapInvToSelf(); 168 169 /** 170 * Element-by-element multiplication. 171 * @param v vector by which instance elements must be multiplied 172 * @return a vector containing this[i] * v[i] for all i 173 * @throws IllegalArgumentException if v is not the same size as this 174 */ 175 public FieldVector<T> ebeMultiply(FieldVector<T> v) 176 throws IllegalArgumentException; 177 178 /** 179 * Element-by-element multiplication. 180 * @param v vector by which instance elements must be multiplied 181 * @return a vector containing this[i] * v[i] for all i 182 * @throws IllegalArgumentException if v is not the same size as this 183 */ 184 public FieldVector<T> ebeMultiply(T[] v) 185 throws IllegalArgumentException; 186 187 /** 188 * Element-by-element division. 189 * @param v vector by which instance elements must be divided 190 * @return a vector containing this[i] / v[i] for all i 191 * @throws IllegalArgumentException if v is not the same size as this 192 */ 193 public FieldVector<T> ebeDivide(FieldVector<T> v) 194 throws IllegalArgumentException; 195 196 /** 197 * Element-by-element division. 198 * @param v vector by which instance elements must be divided 199 * @return a vector containing this[i] / v[i] for all i 200 * @throws IllegalArgumentException if v is not the same size as this 201 */ 202 public FieldVector<T> ebeDivide(T[] v) 203 throws IllegalArgumentException; 204 205 /** 206 * Returns vector entries as a T array. 207 * @return T array of entries 208 */ 209 T[] getData(); 210 211 /** 212 * Compute the dot product. 213 * @param v vector with which dot product should be computed 214 * @return the scalar dot product between instance and v 215 * @exception IllegalArgumentException if v is not the same size as this 216 */ 217 T dotProduct(FieldVector<T> v) 218 throws IllegalArgumentException; 219 220 /** 221 * Compute the dot product. 222 * @param v vector with which dot product should be computed 223 * @return the scalar dot product between instance and v 224 * @exception IllegalArgumentException if v is not the same size as this 225 */ 226 T dotProduct(T[] v) 227 throws IllegalArgumentException; 228 229 /** Find the orthogonal projection of this vector onto another vector. 230 * @param v vector onto which instance must be projected 231 * @return projection of the instance onto v 232 * @throws IllegalArgumentException if v is not the same size as this 233 */ 234 FieldVector<T> projection(FieldVector<T> v) 235 throws IllegalArgumentException; 236 237 /** Find the orthogonal projection of this vector onto another vector. 238 * @param v vector onto which instance must be projected 239 * @return projection of the instance onto v 240 * @throws IllegalArgumentException if v is not the same size as this 241 */ 242 FieldVector<T> projection(T[] v) 243 throws IllegalArgumentException; 244 245 /** 246 * Compute the outer product. 247 * @param v vector with which outer product should be computed 248 * @return the square matrix outer product between instance and v 249 * @exception IllegalArgumentException if v is not the same size as this 250 */ 251 FieldMatrix<T> outerProduct(FieldVector<T> v) 252 throws IllegalArgumentException; 253 254 /** 255 * Compute the outer product. 256 * @param v vector with which outer product should be computed 257 * @return the square matrix outer product between instance and v 258 * @exception IllegalArgumentException if v is not the same size as this 259 */ 260 FieldMatrix<T> outerProduct(T[] v) 261 throws IllegalArgumentException; 262 263 /** 264 * Returns the entry in the specified index. 265 * <p> 266 * The index start at 0 and must be lesser than the size, 267 * otherwise a {@link MatrixIndexException} is thrown. 268 * </p> 269 * @param index index location of entry to be fetched 270 * @return vector entry at index 271 * @throws MatrixIndexException if the index is not valid 272 * @see #setEntry(int, FieldElement) 273 */ 274 T getEntry(int index) 275 throws MatrixIndexException; 276 277 /** 278 * Set a single element. 279 * @param index element index. 280 * @param value new value for the element. 281 * @exception MatrixIndexException if the index is 282 * inconsistent with vector size 283 * @see #getEntry(int) 284 */ 285 void setEntry(int index, T value) 286 throws MatrixIndexException; 287 288 /** 289 * Returns the size of the vector. 290 * @return size 291 */ 292 int getDimension(); 293 294 /** 295 * Construct a vector by appending a vector to this vector. 296 * @param v vector to append to this one. 297 * @return a new vector 298 */ 299 FieldVector<T> append(FieldVector<T> v); 300 301 /** 302 * Construct a vector by appending a T to this vector. 303 * @param d T to append. 304 * @return a new vector 305 */ 306 FieldVector<T> append(T d); 307 308 /** 309 * Construct a vector by appending a T array to this vector. 310 * @param a T array to append. 311 * @return a new vector 312 */ 313 FieldVector<T> append(T[] a); 314 315 /** 316 * Get a subvector from consecutive elements. 317 * @param index index of first element. 318 * @param n number of elements to be retrieved. 319 * @return a vector containing n elements. 320 * @exception MatrixIndexException if the index is 321 * inconsistent with vector size 322 */ 323 FieldVector<T> getSubVector(int index, int n) 324 throws MatrixIndexException; 325 326 /** 327 * Set a set of consecutive elements. 328 * @param index index of first element to be set. 329 * @param v vector containing the values to set. 330 * @exception MatrixIndexException if the index is 331 * inconsistent with vector size 332 * @see #setSubVector(int, FieldElement[]) 333 */ 334 void setSubVector(int index, FieldVector<T> v) 335 throws MatrixIndexException; 336 337 /** 338 * Set a set of consecutive elements. 339 * @param index index of first element to be set. 340 * @param v vector containing the values to set. 341 * @exception MatrixIndexException if the index is 342 * inconsistent with vector size 343 * @see #setSubVector(int, FieldVector) 344 */ 345 void setSubVector(int index, T[] v) 346 throws MatrixIndexException; 347 348 /** 349 * Set all elements to a single value. 350 * @param value single value to set for all elements 351 */ 352 void set(T value); 353 354 /** 355 * Convert the vector to a T array. 356 * <p>The array is independent from vector data, it's elements 357 * are copied.</p> 358 * @return array containing a copy of vector elements 359 */ 360 T[] toArray(); 361 362 }