July 2017 archive

Regional and Locale Settings Affects Parsing Decimal Strings in C#

Yesterday, someone who was trying to use Jackknife, our gesture recognition library, reported that he couldn’t reproduce our results with our C# code. Naturally, we started looking into the issue. Strangely enough, the code worked fine for me (both Debug and Release configurations). I then built the code under multiple versions of Visual Studio, tried …

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Orthonormalize a Rotation Matrix

If you use a 3×3 R matrix to store the result of the multiplication of a series of rotation transformations, it could be the case that sometimes you end up with a matrix that is not orthonormal (i.e. det(R) != 1 and R.inv(R) != eye). In such cases, you need to re-orthonormalize the rotation matrix, …

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