   INSTALLATION:

   LPipe runs on UNIX and UNIX variants (including MacOS).  
   You will need IDL (almost any version will work) and the IDLAstro library
   (see step #4).

   1. Create the subdirectory 'lpipe' somewhere on your hard drive (probably
   in your IDL directory, e.g. /user/yourname/idl/lpipe/).

   2. Download the installation tarball (lpipe.tar.gz) into this subdirectory.
   and unpack it (e.g.,  tar -xvf lpipe.tar.gz).

   3. Tell IDL about the existence of this new directory and its dependencies
   subdirectory by editing the IDL_PATH system variable.  For single-usage you can enter 
   the following line at the command line (depending on your command shell):
     csh:  setenv IDL_PATH $IDL_PATH':+/path/to/lpipe'
     bash: export IDL_PATH=$IDL_PATH':+/path/to/lpipe'
   ...replacing /path/to/ with the appropriate path.  If IDL_PATH is not configured on 
   your system you will need to first set it to point at the IDL core libraries, e.g.:
     csh:  setenv IDL_PATH /usr/local/idl8/idl/lib
     bash: export IDL_PATH=/usr/local/idl8/idl/lib
   For repeat usage, copy the above lines into your .cshrc or .bashrc file instead.

   4. If you do not have the GSFC IDLAstro routines installed, install these (and point
   your IDL_PATH to them) as well.   See http://idlastro.gsfc.nasa.gov/ for instructions.

   5. If you want to perform astrometry and zeropoint calibration on images, you
   will also need to install autoastrometry (a simple, single-file python script;
   download at http://www.astro.caltech.edu/~dperley/programs/autoastrometry.py),
   sextractor (https://www.astromatic.net/software/sextractor), and swarp 
   (https://www.astromatic.net/software/swarp).   LPipe will then need to be pointed
   to these executables for these files by editing the lpipe.par file in the lpipe
   directory.  Additionally, autoastrometry will need to be pointed to sextractor
   by editing the first few lines of autoastrometry.py.   These are not required for
   processing longslit spectroscopy.

   Once installed, the pipeline is run from inside the IDL command line by simply
   typing "lpipe".  For more information, see the manual file or type "lpipe, /help"
   within IDL.  If this does not work, check step #3.

