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/
//
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//
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//   this list of conditions and the following disclaimer.
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// Author: sameeragarwal@google.com (Sameer Agarwal)

#include "ceres/array_utils.h"

#include <cmath>
#include <cstddef>

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