internal/ceres/array_utils.cc

// Ceres Solver - A fast non-linear least squares minimizer
// Copyright 2012 Google Inc. All rights reserved.
// http://code.google.com/p/ceres-solver/
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
//   this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
//   this list of conditions and the following disclaimer in the documentation
//   and/or other materials provided with the distribution.
// * Neither the name of Google Inc. nor the names of its contributors may be
//   used to endorse or promote products derived from this software without
//   specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//
// Author: sameeragarwal@google.com (Sameer Agarwal)

#include "ceres/array_utils.h"

#include <cmath>
#include <cstddef>
#include "ceres/fpclassify.h"

namespace ceres {
namespace internal {

// It is a near impossibility that user code generates this exact
// value in normal operation, thus we will use it to fill arrays
// before passing them to user code. If on return an element of the
// array still contains this value, we will assume that the user code
// did not write to that memory location.
const double kImpossibleValue = 1e302;

bool IsArrayValid(const int size, const double* x) {
  if (x != NULL) {
    for (int i = 0; i < size; ++i) {
      if (!IsFinite(x[i]) || (x[i] == kImpossibleValue))  {
        return false;
      }
    }
  }
  return true;
}

void InvalidateArray(const int size, double* x) {
  if (x != NULL) {
    for (int i = 0; i < size; ++i) {
      x[i] = kImpossibleValue;
    }
  }
}

}  // namespace internal
}  // namespace ceres