Dear Prof Bangerth, Ah. That now was helpful. Thank you! A scrolling screenful of warnings which wrap across multiple lines is pretty intimidating for those not so comfortable with C++.
Hi all, Is there a tutorial or general online resource that folks here would recommend for debugging? Regards, Krishna On Wed, 24 Jun 2020 at 23:54, Wolfgang Bangerth <bange...@colostate.edu> wrote: > On 6/24/20 3:14 PM, Krishnakumar Gopalakrishnan wrote: > > Hi, > > > > I am solving the basic diffusion equation using the direct method (based > on > > Step-52). > > > > I have made the following changes from Step-52 tutorial > > > > 1. The domain is now 1D (as opposed to 2D in step-52) > > 2. We have Neumann BCs on both ends (left NeumannBC = 0.5, right > NeumannBC= 0) > > 3. Removes the code for MMS validation (i.e. no source term S(t)) so > that we > > solve for the unknown field variable, instead of verifying whether the > > pre-formulated analytical solution is retrieved) > > 4. Sets the absorpotion coefficient, Sigma_a = 0 > > 5. Sets a non-zero initial condition (but a spatially constant value). > > > > The C++ source code & Cmakelists.txt files are attached herewith. The > solution > > is indeed correct and is as expected, and I have visualised this in > Paraview. > > However, I'd like to understand the compilation warnings. > > > > Some of them have to do with "unused variables", which are somewhat > > straightforward to get rid of. But the other warnings which all have the > > string "required from here" is not so clear to me. > > Read the error/warning message in its entirety. For example, the first one > says > > /home/bangerth/p/deal.II/1/install/examples/step-1/step-1.cc: In > instantiation > of ‘void DiffusionEqn::SolidDiffusion<dim>::run() [with int dim = 1]’: > /home/bangerth/p/deal.II/1/install/examples/step-1/step-1.cc:441:26: > required from here > /home/bangerth/p/deal.II/1/install/examples/step-1/step-1.cc:420:24: > warning: > variable ‘n_steps’ set but not used [-Wunused-but-set-variable] > unsigned int n_steps = 0; > ^~~~~~~ > > If you strip the details, it says: > > In instantiation of function b() // i.e., while compiling a() > required from here // i.e., we got to a() while > compiling b() > warning: variable unused > > In other words, the compiler isn't just telling you where (in which > function > and line of code) the problem happened, but also *why* it is compiling > this > function (because it's called from some other place) and with which > template > arguments. > > Best > W. > > > > > Can someone please explain what these warnings mean, and what is the > best > > practice for refactoring it to avoid such warnings. > > > > Thanks! > > Krishna > > > > -- > > The deal.II project is located at http://www.dealii.org/ > > < > https://nam01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.dealii.org%2F&data=02%7C01%7CWolfgang.Bangerth%40colostate.edu%7Cfd8a27c47f9a45cc323908d818838c1f%7Cafb58802ff7a4bb1ab21367ff2ecfc8b%7C0%7C0%7C637286300568833692&sdata=D5TEoM8Dk11JtvV6qM7o79260F%2BztbJpQw5M%2FVghgaU%3D&reserved=0 > > > > For mailing list/forum options, see > > https://groups.google.com/d/forum/dealii?hl=en > > < > https://nam01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgroups.google.com%2Fd%2Fforum%2Fdealii%3Fhl%3Den&data=02%7C01%7CWolfgang.Bangerth%40colostate.edu%7Cfd8a27c47f9a45cc323908d818838c1f%7Cafb58802ff7a4bb1ab21367ff2ecfc8b%7C0%7C0%7C637286300568843686&sdata=XWXhcdeMs1Poa%2BSLIqCZH73Wh1wqlvqLyz%2BTXB%2FMvBo%3D&reserved=0 > > > > --- > > You received this message because you are subscribed to the Google > Groups > > "deal.II User Group" group. > > To unsubscribe from this group and stop receiving emails from it, send > an > > email to dealii+unsubscr...@googlegroups.com > > <mailto:dealii+unsubscr...@googlegroups.com>. > > To view this discussion on the web visit > > > https://groups.google.com/d/msgid/dealii/d6aaa13b-5325-4f4a-9493-23859a5bcb9co%40googlegroups.com > > < > https://nam01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgroups.google.com%2Fd%2Fmsgid%2Fdealii%2Fd6aaa13b-5325-4f4a-9493-23859a5bcb9co%2540googlegroups.com%3Futm_medium%3Demail%26utm_source%3Dfooter&data=02%7C01%7CWolfgang.Bangerth%40colostate.edu%7Cfd8a27c47f9a45cc323908d818838c1f%7Cafb58802ff7a4bb1ab21367ff2ecfc8b%7C0%7C0%7C637286300568843686&sdata=4eiKv3%2FUh9%2Bx5zjYczkUfN%2F%2Fwn8M8zpGx%2Fvccf%2FIhjs%3D&reserved=0 > >. > > > -- > ------------------------------------------------------------------------ > Wolfgang Bangerth email: bange...@colostate.edu > www: http://www.math.colostate.edu/~bangerth/ > > -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to dealii+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/dealii/CABvf3kaYvKYGAOj5JBmnOnz1s-wBZ5YwJHAF6HRa7bfjtHbeow%40mail.gmail.com.
