Re: [deal.II] Use of QGauss object in tutorials

2020-10-08 Thread Xuefeng Li
are created with the same number of > points > (given by the argument). > > Best > W. > > Thanks for the confirmation. I was a Java guy. I found C++ quite different (or liberal) in terms of variable declaration, initialization and memory release. That's the reason I asked the qu

[deal.II] Use of QGauss object in tutorials

2020-10-07 Thread Xuefeng Li
enlightenment. -- Stay put, practice social distancing, and be safe! Best, --Xuefeng Li, (504)865-3340(phone) Like floating clouds, the heart rests easy Like flowing water, the spirit stays free Loyola University New Orleans New Orleans, Louisiana (504)865-2051(fax) -- The deal.II

Re: [deal.II] Function apply_boundary_values()

2020-09-28 Thread Xuefeng Li
On Sun, Sep 27, 2020 at 10:33 PM Wolfgang Bangerth wrote: > On 9/25/20 4:15 PM, Xuefeng Li wrote: > > > > For step-26, because system_rhs depends on time and time_step, we need > to > > assemble system_rhs in the loop. We therefore > > need to call apply_boundary_

Re: [deal.II] Function apply_boundary_values()

2020-09-25 Thread Xuefeng Li
On Fri, Sep 25, 2020 at 4:29 PM Wolfgang Bangerth wrote: > On 9/25/20 3:07 PM, Xuefeng Li wrote: > > > > My question is: will the repeated call to function > apply_boundary_values() > > inside the loop > > alter the system_matrix that is meant to be consta

[deal.II] Function apply_boundary_values()

2020-09-25 Thread Xuefeng Li
Hi, there! I have a question concerning the use of the function apply_boundary_values(): MatrixTools::apply_boundary_values(boundary_values, system_matrix, solution, system_rhs);

Re: [deal.II] Accessing nodal values of a FEM solution

2020-07-25 Thread Xuefeng Li
On Fri, Jul 24, 2020 at 9:58 PM Wolfgang Bangerth wrote: > On 7/23/20 12:07 PM, Xuefeng Li wrote: > > > > Well, the above function calculates the gradients of a finite element at > the > > quadrature points of a cell, not at the nodal points of a cell. > > Such

Re: [deal.II] Accessing nodal values of a FEM solution

2020-07-24 Thread Xuefeng Li
practice social distancing, and be safe! Best, --Xuefeng Li, (504)865-3340(phone) Like floating clouds, the heart rests easy Like flowing water, the spirit stays free Loyola University New Orleans New Orleans, Louisiana (504)865-2051(fax) -- The deal.II project is located at http://

Re: [deal.II] Accessing nodal values of a FEM solution

2020-07-23 Thread Xuefeng Li
assFEValuesBase.html#ad1f4e0deb5d982e8172d82141c634a67 > ). > > Well, the above function calculates the gradients of a finite element at the quadrature points of a cell, not at the nodal points of a cell. Such a need arises in the following situation. for ( x in vector_of_nodal_points ) v(x) =

Re: [deal.II] Accessing nodal values of a FEM solution

2020-07-23 Thread Xuefeng Li
int value within the same loop? 2. In addition to nodal point values of a solution, are the partial derivatives (or gradient) of the solution at each nodal point available in deal.ii? Thanks again for any assistance! -- Stay put, practice social distancing, and be safe! Best,

[deal.II] Accessing nodal values of a FEM solution

2020-07-19 Thread Xuefeng Li
Hi, there! I have some general questions about deal.ii, and here is the background info concerning my question. There are two functions u and v, defined over domain \Omega in 1D/2D/3D. We use deal.ii to solve for the numerical approximation of function u, using 1st degree polynomial for

Re: [deal.II] Local tutorial installation missing some examples

2020-04-09 Thread Xuefeng Li
me of the release. You’ll have to download the developer version of > deal.II in order to have a local copy of them. > > I hope that this answers your question! > Best, > Jean-Paul > > On 09 Apr 2020, at 23:02, Xuefeng Li > wrote: > > Hi, all! > > I installed dealii-9.1.

[deal.II] Local tutorial installation missing some examples

2020-04-09 Thread Xuefeng Li
Hi, all! I installed dealii-9.1.1 along with documentation under Ubuntu 18 inside VM VirtualBox on a Win10 PC. I spent the last couple of weeks reading through the tutorial, one example at a time. I also ran some of the examples as suggested by the tutorial. However, my local installation of