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Synopsis


program [key1=]val1 [key2=]val2 .!.!.
runprogram [key1=]val1 [key2=]val2 .!.!.
run program ...

Description

NEMO is a Stellar Dynamics Toolbox for users and programmers. It has various programs to create, integrate and analyze N-body systems. In addition there are various tools to operate on images, tables and orbits, including FITS files to export/import to/from other astronomical data reduction packages.

A good start is the manual page programs(8NEMO) , which lists programs thematically, and index(1NEMO) , which lists them alphabetically (CAVEAT: these pages are often out of date).

NEMO is very much integrated into the Unix(tm) operating system, so users are expected to use standard Unix or Local commands as glue between the various tasks (cat, ls, rm, cp, awk, mongo, sm, etc.). Understanding of shell scripting (sh,csh,python,perl,...) can be very useful. Several example shell scripts exist in the source code to demonstrate how experiments can be orchestrated.

Getting Started

What you need to do to set yourself up for NEMO:

The easiest way is to add the appropriate line to your .cshrc or .bashrc file:

        source $NEMO/nemo-start.csh
or
        source $NEMO/nemo-start.sh

If you need more control over your environment, there are other methods described elsewhere (The NEMO Users/Programmers Guide, Appendix A), or consult one of your local or remote friendly NEMO users.

How to Run Nemo Programs

NEMO programs can be run just as any other command in Unix, in that sense NEMO is nothing more than an extension of Unix.

NEMO programs all work by using a series of keyword=value pairs on the commandline. If the order of the supplied keywords is the same as the program expects them, the keyword= part can be omitted, simply to save keystrokes. There is a consistent ordering of keywords in most programs that allows experienced users to use such (and other) shortcuts. (e.g. in= the first one, out= the second one etc.). Keywords can be used in minimum match, but this is not recommended for shell scripts. To make shell scripts robust, it is recommended you add the keyword= part for all but the first one or two.

NEMO programs make a distinction between program keywords (keywords unique to a program) and system keywords (a fixed set of keywords that each NEMO program understands). The system keywords that you are likely to use are help= and yapp=, and to a lesser degree debug= and error=. The help= gives various types of inline aid from a program. There is also online help on a program, for which unix man(1) command (or any of it’s derived friends) is normally used. The yapp= sets the graphics device used by programs who use a graphics device. You system manager may have given you a default.

Each system keyword can be defaulted by setting it’s equivalent environment variable (in upper case!). Program keywords can be abbreviated to uniqueness.

Examples: Consider the program mkplummer, a program which creates an N-body realization of a Plummer sphere: To get online help, one types:

        man mkplummer
and to get various types of inline help:
        mkplummer help=
        mkplummer help=h
        mkplummer help=’?’
Note the literal quotes around the question-mark needed if you use a regular Unix shell as interface. The first help= reminds you of the order of the program keywords and their default values. The second form, help=h prints out a small one-line reminder what each keyword means. The last form help=’?’ lists various options the user interface understands, this one is not program dependant.

If you chain NEMO programs, pipes can be a very efficient way to prevent large amounts of disk access. Most keywords that operate on files (notably in=, out=, as long as stropen(3NEMO) is used) can use standard piped I/O by using the dash (-) to name the keyword, e.g.

    mkplummer - 100 | tsf -
would create a snapshot of 100 bodies on the fly, and display it to the user using tsf. The alternative would have been
    mkplummer out=tmp nbody=100
    tsf in=tmp
    rm tmp

HOW TO RUN non-NEMO PROGRAMS

Over the times NEMO has incoorporated a number of non-NEMO programs, with varying degrees of input parameter schemes. For a number of them a unified NEMO frontend was developed, usually those programs start with the prefix run. For example, bulgerot comes with runbulgerot. Since often such programs have a hardcoded name for input and/or output files, one simple way to be able to run them in parallel without stepping on filenames, is the use of a clean run directory. Example of this can be found in runbulgerot(1NEMO) , runbody1(1NEMO) , rungalaxy(1NEMO) , runscfm(1NEMO) , runqumond(1NEMO) , and others.

You will find a few common user keywords for this: outdir= is always a required keyword, and needs to be a non-existing directory in which the data is written. For some programs there is an exe= keyword, in order to change the name of the non-NEMO program to be run. This is always assumed to be in the standard Unix search path ($PATH).

Although these run* programs use a fairly common method to run the non-NEMO programs, they have not all been unified as is proposed in run(3NEMO) .

See Also

index(1NEMO) , programs(8NEMO) , tricks(8NEMO) , mkplummer(1NEMO) , files(8NEMO) , nemoinp(1NEMO) , stropen(3NEMO) , getparam(3NEMO) , run(1NEMO) , run(3NEMO) , pipestatus(l)

Author

Peter Teuben (e-mail: teuben@astro.umd.edu phone: 301-405-1540)

Further Information

The NEMO Users/Programmers Guide contains most of the information you need to get down to the guts of the system.

Various man(1NEMO) pages explain programs(1) , subroutine libraries(3) file formats(5) and system management(8) .

The World Wide Web homepage http://www.astro.umd.edu/nemo.

Bugs

Since programs are being modified, and extended fairly regularly, manual pages for related programs do not always know about these changes if they should. Keeping good cross references in the manual pages might help.


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