// Logically collective
dErr dUnitsCreateUnit(dUnits un,const char *type,const char *longname,const char *shortname,dInt n,const dReal expon[],dUnit *newunit)
{
dErr err;
dUnit unit;
dFunctionBegin;
dValidHeader(un,dUNITS_CLASSID,1);
if (n < 1 || n > dUNITS_MAX) dERROR(((dObject)un)->comm,PETSC_ERR_ARG_OUTOFRANGE,"The number of exponents %D must be positive, but no larger than %D",n,(dInt)dUNITS_MAX);
dValidRealPointer(expon,5);
dValidPointer(newunit,6);
err = dUnitsGetEmptyUnit_Private(un,&unit);dCHK(err);
err = PetscStrallocpy(type,&unit->quantity);dCHK(err);
err = dUnitsAssignName(un,dUnitName,longname,n,expon,&unit->longname);dCHK(err);
err = dUnitsAssignName(un,dUnitShortName,shortname,n,expon,&unit->shortname);dCHK(err);
err = dUnitsAssignName(un,dUnitSIName,NULL,n,expon,&unit->siname);dCHK(err);
unit->toSI = 1.0;
unit->toCommon = 1.0;
for (dInt i=0; i<n; i++) {
dUnit base;
err = dUnitsGetBase(un,i,&base);dCHK(err);
unit->toCommon *= PetscPowScalar(dUnitDimensionalize(base,1.0),expon[i]);
unit->toSI *= PetscPowScalar(dUnitDimensionalizeSI(base,1.0),expon[i]);
unit->expon[i] = expon[i];
}
*newunit = unit;
dFunctionReturn(0);
}
/** Set rotation for certain nodes in a function space
*
* @param fs the function space
* @param is index set of nodes to rotate, sequential, with respect blocks of local vector
* @param rot Rotation matrices at all nodes in \a is. Should have length \c bs*bs*size(is).
* @param ns number of dofs to enforce strongly at each node (every entry must have 0<=ns[i]<=bs)
* @param v Vector of values for strongly enforced dofs
*
* @example Consider 2D flow over a bed with known melt rates. Suppose the local velocity vector is
*
* [u0x,u0y; u1x,u1y; u2x,u2y; u3x,u3y | u4x,u4y]
*
* (4 owned blocks, one ghosted block) and nodes 1,4 are on the slip boundary with normal and tangent vectors n1,t1,n4,t4
* and melt rates r1,r4. To enforce the melt rate strongly, use
*
* \a is = [1,4]
* \a rot = [n10,n11,t10,t11, n40,n41,t40,t41]
* \a ns = [1,1]
* \a v = [r1,r4]
*
* The rotated vector will become (. = \cdot)
*
* [u0x,u0y; u1.n1,u1.t1; u2x,u2y; u3x,u3y | u4.n4,u4.t4]
*
* and strongly enforcing melt rate produces the global vector
*
* [u0x,u0y; r1,u1.t1; u2x,u2y; u3x,u3y | r4,u4.t4] .
*
* This is what the solver sees, the Jacobian will always have rows and columns of the identity corresponding to the
* strongly enforced components (2,8 of the local vector) and the residual will always be 0 in these components. Hence
* the Newton step v will always be of the form
*
* [v0x,v0y; 0,v1y; v2x,v2y; v3x,v3y | 0,v4y] .
**/
dErr dFSRotationCreate(dFS fs,IS is,dReal rmat[],dInt ns[],Vec v,dFSRotation *inrot)
{
dFSRotation rot;
dInt bs,n;
dErr err;
dFunctionBegin;
dValidHeader(fs,DM_CLASSID,1);
dValidHeader(is,IS_CLASSID,2);
dValidRealPointer(rmat,3);
dValidIntPointer(ns,4);
dValidHeader(v,VEC_CLASSID,5);
dValidPointer(inrot,6);
*inrot = 0;
err = PetscHeaderCreate(rot,_p_dFSRotation,struct _dFSRotationOps,dFSROT_CLASSID,"dFSRotation","Local function space rotation","FS",PETSC_COMM_SELF,dFSRotationDestroy,dFSRotationView);dCHK(err);
err = dFSGetBlockSize(fs,&bs);dCHK(err);
rot->bs = bs;
err = ISGetSize(is,&n);dCHK(err);
rot->n = n;
err = PetscObjectReference((PetscObject)is);dCHK(err);
rot->is = is;
err = PetscObjectReference((PetscObject)v);dCHK(err);
rot->strong = v;
for (dInt i=0; i<n; i++) {
if (ns[i] < 0 || bs < ns[i]) dERROR(PETSC_COMM_SELF,1,"Number of strong dofs must be between 0 and bs=%d (inclusive)",bs);
/* \todo Check that every rmat is orthogonal */
}
err = dMallocA2(n*bs*bs,&rot->rmat,n,&rot->nstrong);dCHK(err);
err = dMemcpy(rot->rmat,rmat,n*bs*bs*sizeof rmat[0]);dCHK(err);
err = dMemcpy(rot->nstrong,ns,n*sizeof ns[0]);dCHK(err);
*inrot = rot;
dFunctionReturn(0);
}
