libqwt.so.6

The graphical user interface of Elmer
Post Reply
drtspc
Posts: 13
Joined: 23 May 2013, 19:45
Antispam: Yes

libqwt.so.6

Post by drtspc »

I used Elmer in 2013, to solve a problem of temperature induced stresses in film stacks.
I now face a similar problem, so I tried to run ElmerGUI, which I remember liking. I get:

ElmerGUI: error while loading shared libraries: libqwt.so.6: cannot open shared object file: No such file or directory

Now, I find a couple versions of that library around my machine:
1. /home/tscale/qwt/qwt-6.0.2/lib/libqwt.so.6
2. /usr/local/qwt-6.0.2/lib/libqwt.so.6

Is there an easy way to tell ElmerGUI where it can find the library (if that is the problem)?
drtspc
Posts: 13
Joined: 23 May 2013, 19:45
Antispam: Yes

Re: libqwt.so.6

Post by drtspc »

Threads from 2014 and 2016 led me to an answer - and I put this longish reply together for my future self, and hopefully others.

Solution: I edited the .bashrc file to extend LD_LIBRARYPATH:

LD_LIBRARY_PATH=/usr/local/qwt-6.0.2/lib:$LD_LIBRARY_PATH
export LD_LIBRARY_PATH

And it works. And it makes sense. (But not in the context of its history on my machine, as described below.)

Aside: One lesson seems to be that there is no reason to include a lib sub-directory in a LD_LIBRARY_PATH path. Perhaps we all should
know that, but I did not until it was implied in the 2016 thread referenced above (which dealt with other libraries that "could not be found",
after installing Elmer on Ubuntu 16.04).

Per the threads referenced above, it seems that Elmer files were/are placed (Ubuntu) in at least 3 different locations over the last 4 years,
which is fine - except discussions that include locations can confuse novices like myself.

History of Elmer on my Ubuntu (VM on Fusion/Mac MBP): I installed Elmer on Ubuntu 13.04 in May of 2013 (in addition to the multiple-day troublesome installations of qt, and attempts at installing cascade . . . ). It worked for the problem I was solving (much more can be written
about meshing . . . ). Over the 4 years since then, I have upgraded Ubuntu several times, an now run 16.04. I have not tried to run Elmer
again until this week, and don't know why the library could not be found this time around. (Except perhaps some directory structure changes
between 13.04 and 16.04?)

I was impressed with how easy it was to solve the 2013 problem using ElmerGUI: About half a day. So I needed to use it for far less time than
it took to insall "it" - largely because I know how to use paraview and vtu files I generated using Elmer.

As I use ElmerGUI/Elmer to solve my current problem, I notice that it crashes during post-processing. This motivates me to want to install
a newer version of Elmer, but I can count on days of installation and tracking down libraries.

Another aside: The "Elmer VM " that runs on Vbox sounds like a really good idea, but I got the impression the ElmerGUI was not included . . .
Post Reply