mthQR: assert nonzero matrix in qr decomposition
mthQR: assert nonzero matrix in qr decomposition

yangf4/core,yangf4/core,yangf4/core,YetAnotherMinion/core,YetAnotherMinion/core,YetAnotherMinion/core,yangf4/core,yangf4/core,YetAnotherMinion/core,YetAnotherMinion/core