Frequently asked questions
**************************

**Q**: I start ``vdat`` and I get an error finishing with::

    vdat.config.core.ConfigurationError: The file 'vdat_setting.cfg' does not exist

**A**: VDAT needs some configuration file to run. You can retrieve them with the
``vdat_config copy`` command. See :doc:`launching` for more information

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**Q**: When running ``vdat`` I see the following warning::

    UserWarning: 'CUREBIN' environment variable is not set. If the 'curebin'
    option in the configuration file is set to interpolate from 'curebin_env',
    all the vdat commands requiring cure binaries will fail.

What is ``CUREBIN``/``cure`` and why do I need it?

**A**: ``cure`` is a library of programs used to reduce HETDEX data. Most of the
commands shipped with VDAT use some ``cure`` executable. CUREBIN is an
environment variable pointing to the ``cure`` binaries. See :ref:`cure` for
instructions.

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**Q**: It tells me there's no raw or redux directory.

**A**: you probably refers to this error::

    2016-06-01 11:47:39,101 CRITICAL Neither the raw directory '['/path/to/raw']' nor the redux directory '/path/to/redux' exist. This is a problem. Aborting.
    Traceback (most recent call last):
    File "/[...]/bin/vdat", line 9, in <module>
        load_entry_point('vdat', 'gui_scripts', 'vdat')()
    File "/[...]/vdat/libvdat/vdat.py", line 115, in main
        vdatlink.symlink("start symlinking the redux directory")
    File "/[...]/vdat/libvdat/symlink.py", line 71, in symlink
        raise vutil.VDATDirError("The raw and redux directories cannot be"
    vdat.utilities.VDATDirError: The raw and redux directories cannot be found: VDAT cannot run.

VDAT needs data to run. If it's the first time you run it you need to specify
one or more directories containing the raw data, as explained in
:doc:`launching`. Once you have ingested the data, VDAT reloads them and it is
not necessary anymore to provide the raw directory.

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**Q** Why I get "vdat: cannot connect to X server" or "DISPLAY NOT SET" when I
run VDAT?

**A**: VDAT has a GUI based on Qt technologies and requires a working graphical
environment. If you are running it on a remote computer via ``ssh``, make sure
that you enable X11 forwarding with the ``-X`` option.