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Capacity and Reference Points

Method
MultimapContainer
Check size
[[nodiscard]] bool empty() const noexcept;
[[nodiscard]] size_type size() const noexcept;
[[nodiscard]] size_type max_size() const noexcept;
SpatialContainer
Check dimensions
[[nodiscard]] size_t dimensions() const noexcept;
Get max/min values
dimension_type max_value(size_t dimension) const;
dimension_type min_value(size_t dimension) const;

Parameters

  • dimension - index of the dimension for which we want the minimum or maximum value

Return value

  • empty()- true if and only if container (equivalent but more efficient than begin() == end())
  • size() - The number of elements in the container
  • max_size() - An upper bound on the maximum number of elements the container can hold
  • dimensions() - Number of dimensions in the container (same as M, when M != 0)
  • max_value() - Maximum value in a given dimension
  • min_value() - Minimum value in a given dimension

Complexity

\[ O(1) \]

Notes

Because all container nodes keep their minimum bounding rectangles, we can get these values in constant time.

Example

Continuing from the previous example:

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if (!m.empty()) {
    std::cout << "Map is not empty" << std::endl;
} else {
    std::cout << "Map is empty" << std::endl;
}
std::cout << m.size() << " elements in the spatial map" << std::endl;
std::cout << m.dimensions() << " dimensions" << std::endl;
for (size_t i = 0; i < m.dimensions(); ++i) {
    std::cout << "Min value in dimension " << i << ": " << m.min_value(i) << std::endl;
    std::cout << "Max value in dimension " << i << ": " << m.max_value(i) << std::endl;
}

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if m:
    print('Map is not empty')
else:
    print('Map is empty')

print(len(m), 'elements in the spatial map')
print(m.dimensions(), 'dimensions')
for i in range(m.dimensions()):
    print('Min value in dimension', i, ': ', m.min_value(i))
    print('Max value in dimension', i, ': ', m.max_value(i))

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Map is not empty
20 elements in the spatial map
3 dimensions
Min value in dimension 0: -2.57664
Max value in dimension 0: 1.49101
Min value in dimension 1: -1.52034
Max value in dimension 1: 3.24052
Min value in dimension 2: -2.92346
Max value in dimension 2: 2.78224