On 30 May 2011 21:02, Anders Logg <l...@simula.no> wrote: > On Mon, May 30, 2011 at 05:37:17PM -0000, Garth Wells wrote: >> Some of these results are anomalies, and some are to be expected. >> >> In all cases, if the quadrature order for the projection operation is >> increased, then the computed results are as expected. >> >> For some cases, the prescribed quadrature scheme is not sufficient to >> integrate the projection, hence the NaN > > Are any of the results caused by the FFC not detecting the right > quadrature rule to use when autodetecting the degree? > > -- > Anders
If the autodetection of degree doesn't even cover projection I would say it should be more conservative... Martin -- You received this bug notification because you are a member of DOLFIN Team, which is subscribed to DOLFIN. https://bugs.launchpad.net/bugs/785874 Title: Projection of x is not accurate Status in DOLFIN: New Bug description: I've tested that projecting x works without the scaling bug that was just fixed, using dimensions 1,2,3 and both DG and CG from 0 to 3 degrees. I print the max and min values of the vector of the projection function, and the values are _close_ to 0 and 1 but not to machine precision. The script is below. There's up to 2.7% error in the 3D case. Is the projection form integrated accurately enough? All but the DG0 function space should be capable of representing x exactly. Not sure if this is a dolfin or ffc bug. from dolfin import * def mcx(dim): if dim == 1: mesh = UnitInterval(20) cell = interval x = cell.x if dim == 2: mesh = UnitSquare(20, 20) cell = triangle x = cell.x[0] if dim == 3: mesh = UnitCube(20, 20, 20) cell = tetrahedron x = cell.x[0] return mesh, cell, x for dim in range(1, 4): mesh, cell, x = mcx(dim) minval, maxval = 1.0, 0.0 #print dim, "DG" for degree in range(3): V = FunctionSpace(mesh, "DG", degree) u = project(x, V) #print dim, degree, u.vector().min(), u.vector().max() minval = min(minval, u.vector().min()) maxval = max(maxval, u.vector().max()) #print dim, "CG" for degree in range(1, 4): V = FunctionSpace(mesh, "CG", degree) u = project(x, V) #print dim, degree, u.vector().min(), u.vector().max() minval = min(minval, u.vector().min()) maxval = max(maxval, u.vector().max()) print minval, maxval _______________________________________________ Mailing list: https://launchpad.net/~dolfin Post to : dolfin@lists.launchpad.net Unsubscribe : https://launchpad.net/~dolfin More help : https://help.launchpad.net/ListHelp
