{"action":"created","issue":{"url":"https://api.github.com/repos/idaholab/moose/issues/6679","repository_url":"https://api.github.com/repos/idaholab/moose","labels_url":"https://api.github.com/repos/idaholab/moose/issues/6679/labels{/name}","comments_url":"https://api.github.com/repos/idaholab/moose/issues/6679/comments","events_url":"https://api.github.com/repos/idaholab/moose/issues/6679/events","html_url":"https://github.com/idaholab/moose/issues/6679","id":145606481,"number":6679,"title":"Material Auxs at specified quad points","user":{"login":"WilkAndy","id":6676821,"avatar_url":"https://avatars.githubusercontent.com/u/6676821?v=3","gravatar_id":"","url":"https://api.github.com/users/WilkAndy","html_url":"https://github.com/WilkAndy","followers_url":"https://api.github.com/users/WilkAndy/followers","following_url":"https://api.github.com/users/WilkAndy/following{/other_user}","gists_url":"https://api.github.com/users/WilkAndy/gists{/gist_id}","starred_url":"https://api.github.com/users/WilkAndy/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/WilkAndy/subscriptions","organizations_url":"https://api.github.com/users/WilkAndy/orgs","repos_url":"https://api.github.com/users/WilkAndy/repos","events_url":"https://api.github.com/users/WilkAndy/events{/privacy}","received_events_url":"https://api.github.com/users/WilkAndy/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":0,"created_at":"2016-04-04T07:25:35Z","updated_at":"2016-04-04T15:24:39Z","closed_at":null,"body":"Could we discuss the following?  Tagging @hsheldon\r\n\r\nIn tensor mechanics we often want to output Material values as AuxVars, e.g. stresses, internal parameters, yield function values, and so on.  Currently with the usual CONSTANT MONOMIAL AuxVariables we see the values averaged over the element.  It would be useful in certain instances to see them at a specified quad point.\r\n\r\nThe solid_mechanics/src/aux/MaterialTensorAux has this ability to specify the quadpoint you're interested in.\r\n\r\nI think i'm asking two questions:\r\n\r\n(1) Do people think this is dumb, or implementable with a simple change to the input file?\r\n\r\n(2) Where/how should it be implemented.  Eg, right in framework/src/auxkernels/AuxKernel.C , or in individual derived classes, or somewhere intermediate (like MaterialAuxBase, but i'm not sure how to actually do that in practice), or somehow else?\r\n"},"comment":{"url":"https://api.github.com/repos/idaholab/moose/issues/comments/205348033","html_url":"https://github.com/idaholab/moose/issues/6679#issuecomment-205348033","issue_url":"https://api.github.com/repos/idaholab/moose/issues/6679","id":205348033,"user":{"login":"permcody","id":3036960,"avatar_url":"https://avatars.githubusercontent.com/u/3036960?v=3","gravatar_id":"","url":"https://api.github.com/users/permcody","html_url":"https://github.com/permcody","followers_url":"https://api.github.com/users/permcody/followers","following_url":"https://api.github.com/users/permcody/following{/other_user}","gists_url":"https://api.github.com/users/permcody/gists{/gist_id}","starred_url":"https://api.github.com/users/permcody/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/permcody/subscriptions","organizations_url":"https://api.github.com/users/permcody/orgs","repos_url":"https://api.github.com/users/permcody/repos","events_url":"https://api.github.com/users/permcody/events{/privacy}","received_events_url":"https://api.github.com/users/permcody/received_events","type":"User","site_admin":false},"created_at":"2016-04-04T15:24:39Z","updated_at":"2016-04-04T15:24:39Z","body":"I think it's worth stepping back and understanding why the AuxSystem and Materials are fundamentally different. The AuxSystem is full of discretized variables just like the nonlinear system. The only difference is that you are explicitly computing the values rather than solving a linear system. At the end of the day your \"quadrature point\" information is used to setup the coefficients so for the shape functions so we can't guarantee that you'll recover the information at the quadrature points \"exactly\" the same way as it goes in. \r\n\r\nNow we DO support higher order monomials so you aren't limited to just CONSTANT MONOMIAL. If you use a higher order you should be fairly close to getting back your exact same values depending on the order. There may be a few bugs that we need to work out here but it should be pretty close, there are even tests in the moose-test suite.\r\n\r\nThe material system was designed so you could compute exact values at quadrature points per element and furthermore, those values don't even have to be just double-precision. They can be rich types like vectors or tensors.\r\n\r\nCould you just use a sufficiently high monomial order to get you past your current hurdle?"}}