[deal.II] What are Deal.II killer features when comparing against Comsol?
Any Comsol users switched to Deal.II to share their experience? Or using both Deal.II and Comsol on everyday tasks? Some questions behind this: 1) How I can motivate my colleagues to try Deal.II? 2) What are possible arguments to invest time into Deal.II instead of buying one more Comsol license? My thought on this (still I am not actually using any of them, so any comments are welcome): 1) License cost? Comsol license is quite expensive. However, if you put the scientist salary on the board, it is not that straightforward. With Comsol it is quite easy to become productive from day zero. To achieve the same technical level with Deal.II you will need few weeks or even months of everyday use... There are so many technical details under the hood hidden from Comsol user which you are forced to be aware of with Deal.II. And even after mastering them both it looks like using Comsol to create a new model (with new geometry and physics) is cheaper compared to deal.ii as soon as you already have a license. And this works even better when you scale up - for sure you need much less number of licenses than a stuff count in the lab.. 2) Control. This is a real benefit from my point of view. You can put the C++ into version control system and get all the improvements with simple diff. Probably Comsol has some kind of "model review mode" to show all check boxes and list choices, however, I was not able to locate this feature fast. 3) Adaptive mesh with hanging nodes. It seems to be a unique Deal.II feature to be able to do a local refinement or coarsening of the model. For sure it is very good, especially for large-scale simulations. The side effect is that it is very natural to do hp-refinement. For time domain problems it is easy for Deal.II to follow with dense mesh alongside with places, where it is actually needed. 4) Large models for HPC This is mostly related to engenering tasks. However, if you have a large problem it can be easier to solve it with Deal.II using HPC cluster. Using 100-1000 cores or more to get the result can speed up the progress a lot, and such kind of clusters are quite affordable our days, it is quite easy to get a HPC access for academic research. It looks like it is not feasible with Comsol (at list I was not able to get data on more than a 20x parallel speedup with 0.8 efficiency for Comsol 4.2 in the internet). 5) Comsol is an integrated environment. So it has the drawing, meshing, setting the model, evaluation, visualisation in the same window, which is rather convenient. Actually this an argument aginst Deal.II, where you should mostly rely on external tools for most of the tasks. It is not a crucial problem, however, it complicates it a bit, e.g. to set up a working environment or to become really productive... Any comments on this? More killer features of Deal.ii are welcome! Best regards, Konstantin Ladutenko -- 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. For more options, visit https://groups.google.com/d/optout.
Re: [deal.II] Could not find LAPACK library
I've fixed the problem, though I'm not quite sure what the problem was. I'm posting this in case someone runs into a similar issue. The fix was to completely uninstall the "redundant" versions of the library (ATLAS, OpenBLAS, etc.) which I had installed to fix other issues. The initial versions of BLAS and LAPACK packaged with Ubuntu are sufficient. I ran a clean build and everything works as expected. On Thursday, September 22, 2016 at 1:22:14 PM UTC-4, Andrew Lambe wrote: > > Here it is: > > andrew@andrew-apple-laptop:~/dealii-8.3.0/build$ ls -l /usr/lib/liblapack* > lrwxrwxrwx 1 root root 29 Sep 21 11:54 /usr/lib/liblapack.a -> > /etc/alternatives/liblapack.a > lrwxrwxrwx 1 root root 28 Nov 23 2015 /usr/lib/liblapack_atlas.a -> > atlas-base/liblapack_atlas.a > lrwxrwxrwx 1 root root 29 Nov 23 2015 /usr/lib/liblapack_atlas.so -> > atlas-base/liblapack_atlas.so > lrwxrwxrwx 1 root root 31 Nov 23 2015 /usr/lib/liblapack_atlas.so.3 -> > atlas-base/liblapack_atlas.so.3 > lrwxrwxrwx 1 root root 30 Sep 21 11:54 /usr/lib/liblapack.so -> > /etc/alternatives/liblapack.so > lrwxrwxrwx 1 root root 32 Sep 15 12:19 /usr/lib/liblapack.so.3 -> > /etc/alternatives/liblapack.so.3 > lrwxrwxrwx 1 root root 34 Sep 15 15:51 /usr/lib/liblapack.so.3gf -> > /etc/alternatives/liblapack.so.3gf > > > > On Thursday, September 22, 2016 at 1:16:27 PM UTC-4, Wolfgang Bangerth > wrote: >> >> On 09/22/2016 11:13 AM, Andrew Lambe wrote: >> > I'm trying to include the bundled UMFPACK package in my deal.II >> > installation, but when I switch the options DEAL_II_WITH_LAPACK and >> > DEAL_II_WITH_UMFPACK on, I get a weird error from CMake that the LAPACK >> > library is not detected. I say weird because I have installed BLAS and >> > LAPACK in the default location /usr/lib (via Ubuntu packages). If I >> > switch these options off, the configuration and compile run without >> > issue. Specifying the directory via the LAPACK_DIR option doesn't help. >> > >> > Unfortunately, I need UMFPACK to run some of my existing examples so I >> > want those options to be on. I recently upgraded my Ubuntu version via >> a >> > fresh install, so this could be the source of the issue, (missing >> > package, broken link, etc.) but I'm having trouble chasing it down. >> > >> > I have included the terminal output with the above options off >> > (terminal_out_ok.txt) and on (terminal_out_bad.txt) as well as the >> error >> > logs for the second case. Any help would be appreciated. >> >> Andrew, >> can you post the output of >>ls -l /usr/lib/liblapack* >> or of >>ls -l /usr/lib64/liblapack* >> depending on whether you have a 32 or 64 bit system? >> >> Best >> W. >> >> -- >> >> Wolfgang Bangerth email: bang...@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. For more options, visit https://groups.google.com/d/optout.
