1 // Ceres Solver - A fast non-linear least squares minimizer 2 // Copyright 2012 Google Inc. All rights reserved. 3 // http://code.google.com/p/ceres-solver/ 4 // 5 // Redistribution and use in source and binary forms, with or without 6 // modification, are permitted provided that the following conditions are met: 7 // 8 // * Redistributions of source code must retain the above copyright notice, 9 // this list of conditions and the following disclaimer. 10 // * Redistributions in binary form must reproduce the above copyright notice, 11 // this list of conditions and the following disclaimer in the documentation 12 // and/or other materials provided with the distribution. 13 // * Neither the name of Google Inc. nor the names of its contributors may be 14 // used to endorse or promote products derived from this software without 15 // specific prior written permission. 16 // 17 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 18 // AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 // IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 // ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE 21 // LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 22 // CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 23 // SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 24 // INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 25 // CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 26 // ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 27 // POSSIBILITY OF SUCH DAMAGE. 28 // 29 // Author: sameeragarwal (at) google.com (Sameer Agarwal) 30 // 31 // Utility routines for validating arrays. 32 // 33 // These are useful for detecting two common class of errors. 34 // 35 // 1. Uninitialized memory - where the user for some reason did not 36 // compute part of an array, but the code expects it. 37 // 38 // 2. Numerical failure while computing the cost/residual/jacobian, 39 // e.g. NaN, infinities etc. This is particularly useful since the 40 // automatic differentiation code does computations that are not 41 // evident to the user and can silently generate hard to debug errors. 42 43 #ifndef CERES_INTERNAL_ARRAY_UTILS_H_ 44 #define CERES_INTERNAL_ARRAY_UTILS_H_ 45 46 #include "ceres/internal/port.h" 47 48 namespace ceres { 49 namespace internal { 50 51 // Fill the array x with an impossible value that the user code is 52 // never expected to compute. 53 void InvalidateArray(int size, double* x); 54 55 // Check if all the entries of the array x are valid, i.e. all the 56 // values in the array should be finite and none of them should be 57 // equal to the "impossible" value used by InvalidateArray. 58 bool IsArrayValid(int size, const double* x); 59 60 // If the array contains an invalid value, return the index for it, 61 // otherwise return size. 62 int FindInvalidValue(const int size, const double* x); 63 64 // Utility routine to print an array of doubles to a string. If the 65 // array pointer is NULL, it is treated as an array of zeros. 66 void AppendArrayToString(const int size, const double* x, string* result); 67 68 extern const double kImpossibleValue; 69 70 // This routine takes an array of integer values, sorts and uniques 71 // them and then maps each value in the array to its position in the 72 // sorted+uniqued array. By doing this, if there are are k unique 73 // values in the array, each value is replaced by an integer in the 74 // range [0, k-1], while preserving their relative order. 75 // 76 // For example 77 // 78 // [1 0 3 5 0 1 5] 79 // 80 // gets mapped to 81 // 82 // [1 0 2 3 0 1 3] 83 void MapValuesToContiguousRange(int size, int* array); 84 85 } // namespace internal 86 } // namespace ceres 87 88 #endif // CERES_INTERNAL_ARRAY_UTILS_H_ 89
