getIndex() Unable to Obtain Index for Maximum Negative Length of Map

[BruceChanJianLe]

My grid_map is geometry size is as below:

map_.setGeometry(grid_map::Length(1.0, 1.0), 0.05, grid_map::Position(0.0, 0.0));

When my position is -0.5 (return from getClosestPositionInMap()), which is still valid in the map, I get the error of

/usr/include/eigen3/Eigen/src/Core/DenseCoeffsBase.h:365: Eigen::DenseCoeffsBase<Derived, 1>::Scalar& Eigen::DenseCoeffsBase<Derived, 1>::operator()(Eigen::Index, Eigen::Index) [with Derived = Eigen::Matrix<float, -1, -1>; Eigen::DenseCoeffsBase<Derived, 1>::Scalar = float; Eigen::Index = long int]: Assertion `row >= 0 && row < rows() && col >= 0 && col < cols()' failed.

However, if my position is 0.5 (return from getClosestPositionInMap()), I do not get the error, and I am able to obtain the index.

I specifically mentioned getClosestPositionInMap() function as I am not sure whether should the getClosestPositionInMap() return something like -0.49 instead of -0.5, or is this a bug inside of getIndex().

Below code will fail when any of the x or y position is -0.5 which is the maximum negative length of the map.

if(map_.getIndex(points_["point_a"], index_a_)
&& map_.getIndex(points_["point_b"], index_b_))
 {
    // Loop through line region
    for(grid_map::LineIterator itr(map_, index_a_, index_b_); !itr.isPastEnd(); ++itr)
    {
        // Change value from 0.0 to 1.0
        map_.at("type", *itr) = 1.0;
        // Publish map
        publish();
    }
}

Thank you for taking your time to look into this matter:D

[maximilianwulf]

Hey @BruceChanJianLe, thank you for submitting the bug. Could you submit a short unit test into this file: https://github.com/ANYbotics/grid_map/blob/master/grid_map_core/test/GridMapTest.cpp. I guess you can copy the code from above.

[BruceChanJianLe]

Hi @maximilianwulf, thanks for getting back. I have submitted a short unit test as requested in #275. Please have a look at the failing test NegativeClosestPositionInMap. Thank you:D

[maximilianwulf]

Thank you, we will have a look at it.

[BruceChanJianLe]

You're welcome! Thank you for taking your time to look into this issue.

[maximilianwulf]

Hey @BruceChanJianLe, indeed the function getClosestPositionInMap gives values at the border of the map, which can in some cases lead to indices outside of the map. I made a fix that should make the function save. It will be merged in the coming days. Thank you for reporting the issue.

[BruceChanJianLe]

Hi @maximilianwulf, thank you for looking into this issue, appreciate your time and contribution to the community. Please remember to close this issue when the fix is merged, before that, I shall leave this issue as open. Thanks again and take care!

[maximilianwulf]

Hey @BruceChanJianLe, a fix is on the way. Let me know if you have further issues.

[BruceChanJianLe]

Hi @maximilianwulf, thanks for looking into this is issue. I will be looking forward to the fix! Thank you:)

[maximilianwulf]

You can check out this commit f1344bd

[BruceChanJianLe]

Wonderful! I will test on it when it is successfully merged into master branch. Thank you @maximilianwulf !