Two out of three least-square gradient options (_lstsq, lstsqdm) have yet undiscovered bugs and give wrong results. The problem is not high priority since _lstsqqr option works well. This is the gradient calculation procedure explained in the reference paper.
Anyhow, it would be nice to discover and remove these bugs and enable users more options for cell centered gradient computation.
Two out of three least-square gradient options (_lstsq, lstsqdm) have yet undiscovered bugs and give wrong results. The problem is not high priority since _lstsqqr option works well. This is the gradient calculation procedure explained in the reference paper. Anyhow, it would be nice to discover and remove these bugs and enable users more options for cell centered gradient computation.