Configuration Options

The behavior of the NEST executable can be tweaked by supplying it with command line switches, SLI scripts, and additional parameters for the scripts.

Command line switches for the nest executable

Type

nest --help

to find out about NEST’s command-line parameters.

usage: nest [options] [ - | file [file ...] ]
  file1 file2 ... filen     read SLI code from file1 to filen in ascending order
                            Quits with exit code 126 on error.
  -   --batch               read SLI code from stdin/pipe.
                            Quits with exit code 126 on error.
  -c cmd                    Execute cmd and exit
  -h  --help                print usage and exit
  -v  --version             print version information and exit
      --userargs=arg1:...   put user defined arguments in statusdict::userargs
  -d  --debug               start in debug mode (implies --verbosity=ALL)
      --verbosity=ALL       turn on all messages.
      --verbosity=DEBUG|STATUS|INFO|WARNING|ERROR|FATAL
                            show messages of this priority and above.
      --verbosity=QUIET     turn off all messages.

SLI scripts

Scripts can be run by typing:

<nest_install_dir>/nest <file>

If you are a Vim user and require support for SLI files, please refer to our Vim support for SLI files.

Supplying SLI scripts with parameters

Using the --userargs=arg1:... command line switch, it is possible to supply a SLI script with parameters from the outside of NEST. A common use case for this are parameter sweeps, where the parameters are defined in a bash script and multiple instances of NEST are used to test one parameter each. A bash script for this could look like this:

for lambda in `seq 1 20`; do
  for gamma in `seq 1 5`; do
    nest --userargs=lambda=$lambda:$gamma=$gamma simulation.sli
  done
done

The corresponding SLI script simulation.sli could use the supplied parameters like this:

/args mark statusdict/userargs :: {(=) breakup} Map { arrayload pop int exch cvlit exch } forall >> def
args /lambda get ==

The first line first gets the array of user supplied arguments (userargs) from the statusdict and breaks each element at the “=”-symbol. It then converts the first element (lambda, gamma) to a literal and the second argument (the number) to an integer. Using mark and >>, the content of the userargs array is added to a dictionary, which is stored under the name args. The second line just prints the content of the lambda variable.