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snapprint - print out items of a snapshot in table format
snapprint produces a table of
values of requested quantities of the bodies in a snapshot. These can be
processed with programs such as tabhist, tablsqfit or packages such as
mongo, super-mongo and gnuplot. If your processing package is able to read
other types of nbody formats, look at programs such as snapgadget(1NEMO)
, or snaptipsy(1NEMO)
snapprint also has an option of producing
a table of separations between all bodies of the system. For N bodies this
table will have a length of N(N-1)/2, hence the keyword separ will for any
non-zero value produce a list which is nsep times smaller and print only
The following parameters are recognized in
any order if the keyword is also given:
not work, returns btab=NULL, bits=1, i.e. something weird here. Code is identical
to snapcenter, which uses same technique.
- input file, in snapshot(5NEMO)
format [no default]
- List of data-items which will be
listed, any of the bodytrans(3NEM0)
functions can be used in an arbitry
expression. [default: x,y,z,vx,vy,vz].
- Valid C-format descriptor
used in printf(3)
to output the numbers. [default: %g].
will for any non-zero value turn off all above options and produce a single
table of the logarithm of the separations between the bodies. Only every
nsepth entry (the stride) of all N(N-1)/2 combinations will be listed [default:
- Time values/intervals of which snapshots should be
used. Default is empty string, which will only extract the first snapshot.
- If a filename is specified, the table is output to this file.
If none, output will be standard output. [default: no file].
a header to the output? The header will contain the number of particles,
followed by the timestamp, of the snapshot. If masses, position and velocities
are output in the table, this format is also referred to as the ntmpv(5NEMO)
format. [Default: f]
- Should newlines be added between the header elements?
- newline=f|t [Default: f]
- Use CSV (comma separated values) output
style. This means a comma, instead of a space, will be used to separate
the values in the output stream. Default: false.
The inversion function of snapprint,
reading a snapshot from a simple table, could be done with tabtos(1NEMO)
Another route is the somewhat complicated ascii file, consisting of a
number of catenated tables, that has to be created with a little header.
See the "205" format in atos(1NEMO)
. There are shell scripts
which handle some of the cases here.
A single expression like atan2(y,x)
is parsed into two.
, mongo users-manual
~/src/pjt/nbody snapprint.c snapprint.1
18-Mar-88 V1.0: created PJT
15-Apr-88 V1.1: more options PJT
6-jun-88 V1.2: new filestruct, added separ keyword PJT
27-sep-88 V1.3: changed to options keyword PJT
7-feb-89 V1.5: times= added PJT
10-feb-89 V1.6: bodytrans can be used PJT
25-may-90 V1.8: added tab= keyword PJT
7-jul-97 (V2.0) documented header= PJT
4-sep-03 V2.2: added csv= PJT
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