README for simple-grape (for GRAPE-6)

Copyright J. Makino 2001

Version 0.0 May 16, 2001, Jun Makino

1) Installing simple-grape

On Digital UNIX systems,

% make

should do

On Linux/Alpha systems

% make -f Makefile.g6linux

should do

2) Sample run
Here, testparm is the name of the parameter file (see section 3)

% grape6 < testparm

.....
.....
.....
.....

T=       4.500  E =    -0.253143294  
DE=-4.91996143e-04  V.R. =   0.499034
T=       4.500  E =    -0.253143294  
DE=-4.91996143e-04  V.R. =   0.499034
CM : 1.30755e-16 -2.29038e-18 -1.54499e-17
CMV: 4.18299e-17  8.83625e-18  1.40675e-17
AM : 5.19160e-03 -3.95216e-03  3.94282e-04
Exit  diag:CPU sec.=       16.73
Enter diag:CPU sec.=       17.87
CPU sec.=       17.87
T=       5.000  E =    -0.253148379  
DE=-4.71895792e-04  V.R. =   0.497748
T=       5.000  E =    -0.253148379  
DE=-4.71895792e-04  V.R. =   0.497748
CM : 1.36325e-16 -4.92634e-18 -9.92045e-18
CMV: 4.43778e-17  4.87891e-19  8.53809e-18
AM : 5.19160e-03 -3.95216e-03  3.94282e-04
Exit  diag:CPU sec.=       17.87

3) Input parameter file format

-----------------------------------
0.03125 5 0.5 0.03125  0.015625
pl8k.ascii
~
-----------------------------------
Meaning:
dt tstop dtout dtsnapout eps
input file name
output file name

dt: integration stepsize
tstop: time to stop integration
dtout: interval for log output (like the one above)
dtsnapout: interval for N-body sytem snapshot output
input file name: name for input N-body snapshot file
output file name: name for output N-body snapshot file
                  "~" means no output

4) Input/Output snapshot file format

The format is so-called NEMO stoa format (see
http://bima.astro.umd.edu/nemo/) for what is NEMO.

In short, the format is

N
Ndim (must be 3...)
time
mass[0]
...
mass[N-1]
x[0][0] x[0][1] x[0][2]
...
x[N-1][0] x[N-1][1] x[N-1][2]
v[0][0] v[0][1] v[0][2]
...
v[N-1][0] v[N-1][1] v[N-1][2]
pot[0]
...
pot[N-1]

For multiple (time-sequence output, the above structure is just
repeated.

Good luck!



