Dear all,
I found out that calling
MGTransferBlockMatrixFree< dim, Number > ::clear
sets the number of blocks to 0/ It is followed directly by build(dofs); will thow an exeption:
Additional information:
Dimension 0 not equal to 2.
There is no way to set number of block properly other than using
MGConstrainedDoFs . In case of DG where there are no constrains this requires creating dummy objects.
Moreover the default contructor (without parameters) does not work (error in compilation - deleted function). Using it could be useful for DG. I would suggest:
1) adding constuctor with number of blocks
2) adding function that sets number of blocks
Best
Michal