[FAQ] No choices given for rhyolite-MELTS / pMELTS graphical user interface

[Paula]

We occasionally get messages that go something like this:

I want to use the mixed H2O-CO2 fluid model and the MELTS decision tree says I should use v1.20 ... or ... I want to select the pMELTS model. However, when I open the rhyolite-MELTS program that I downloaded it goes straight to v1.02.

The problem is probably that the user double-clicked the Melts-rhyolite-public executable (or a link to it) to start the program. On Mac, if the Melts-rhyolite-public file is double-clicked it will open in the Terminal program, and the graphical user interface is not started until the use chooses between rhyolite-MELTS 1.0.2, 1.1.0, 1.2.0, and pMELTS (though on Mac there may be other issues with double-clicking). On some combinations of Linux and desktop environment, even if the user select 'Open in Terminal', the terminal program closes without waiting for the user's input. So the GUI is started with the default model, i.e. rhyolite-MELTS 1.0.2. A better approach is to open the terminal program first. Navigate to the folder where the Melts-rhyolite-public is located, using 'cd path_to_MELTS' (cd = 'change directory'). Then type './Melts-rhyolite-public'.

Whilst it is an improvement on double-clicking the Melts-rhyolite-public executable, always running rhyolite-MELTS in the same place can also be problematic. You need to explicitly move all the .tbl files out of the folder between rhyolite-MELTS runs. Otherwise, if the phase assemblage differs between run 1 and run 2, melts.out and all the .tbl files for phases in run 2 will be overwritten but any other .tbl files from run 1 will still be hanging around. If you use the Combine tbl function from MELTS for Excel you will get a mixture of results from both runs.

Better is to make sure Melts-rhyolite-public, or a link to it, is in your Path. That way you can make a new folder for the current run's output (e.g. melts_output_folder) and open rhyolite-MELTS in it the (empty) folder via Terminal. When you are finished the run, melts.out and all the .tbl files should be in melts_output_folder. On the VM alphaMELTS platform, we have already set this up for you. So you can simply type 'Melts-rhyolite' at the terminal command line (note there is no './' before 'Melts-rhyolite').

Otherwise, if you have installed alphaMELTS, and used the default settings then the '~bin' folder should be in your path. You can check by typing:

echo $PATH

You can either put the Melts-rhyolite-public executable in the 'bin' folder or you can put it elsewhere and make a link to it using 'ln' (type 'man ln' or check out the similar Mac-based post if you are unfamiliar with this command). If you have installed alphaMELTS, but you did not use the default location for the links_folder (i.e. '~/bin') then substitute links_folder for 'bin'.

Alternatively, you may have something like the following in your .profile file by default (type 'cat ~/.profile' to check):

# ~/.profile: executed by the command interpreter for login shells.
# This file is not read by bash(1), if ~/.bash_profile or ~/.bash_login
# exists.

# set PATH so it includes user's private bin if it exists
if [ -d "$HOME/bin" ] ; then
    PATH="$HOME/bin:$PATH"
    export PATH
fi

If that is the case, then you can simply make a bin directory in your home space ('mkdir ~/bin'). Otherwise, you can edit .profile, .bash_profile, or .bashrc (or the appropriate file if bash is not your default shell). Set the path to point to your choice of directory and make a link there to Melts-rhyolite-public.

Alternative approach - make a desktop file that can be double-clicked

On the latest VM alphaMELTS virtual machines (downloaded November 20th, 2017 or later) we provide a 'Melts-rhyolite' icon that can be double-clicked. You can tell that 'Melts-rhyolite' can be double-clicked if its icon picture has an M in the middle of a stylized AFM plot (as opposed to a cog). Rhyolite-MELTS is opened in Lubuntu's terminal program, LXterminal, and the user is given the usual choice between rhyolite-MELTS 1.0.2, 1.1.0, 1.2.0, and pMELTS before the GUI starts.

The Melts-rhyolite.desktop file is a text file, that could easily be adapted to work on other systems:

[Desktop Entry]
Version=1.2.0
Name=Melts-rhyolite
Comment=Choose between rhyolite-MELTS 1.0.2, 1.1.0, 1.2.0, and pMELTS
Exec=lxterminal -e Melts-rhyolite
Icon=/home/melts/MELTS/rhyoliteMelts/meltsicon.png
Terminal=false
Type=Application
Categories=Utility;Application;

'Melts-rhyolite' is the link to the Melts-rhyolite-public executable and is in the user's Path in the VM alphaMELTS installation. 'Melts-rhyolite' could be replaced by the full path to the executable ('/home/melts/MELTS/rhyoliteMelts/Melts-rhyolite-public' in this case). Note, however, that if you use rhyolite-MELTS .desktop file like this, the program will always open in the melts home space ('/home/melts'). So, as noted above, some care will be needed to make sure that results from different runs are not mixed together.

Hope this helps!
Paula