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Name

snapinert - calculate momentum of inertia of a snapshot

Synopsis

snapinert in=snapshot out=out-file [parameter=value]

Description

snapinert calculates the momentum of inertia of a snapshot. The output is ASCII and consists of three parts:

1) Time

2) Moment of inertia tensor

3) Eigenvalues and Eigenvectors of (2) .

The program snapkinem(1NEMO) does similar things - ideas should be combined.

Parameters

The following parameters are recognized in any order if the keyword is also given:
in=in-file
input file, must be in SnapShot(5) format [no default].
out=out-file
output file, ASCII format [no default]
times=time-range
Only data frames with time values within time-range, which is of the form, eg, "1.0:1.5,2.5,3.0", will be translated. [default: all].
weight=expression
The value of expression is used to compute the center of the coordinate and also the momentum of inertia. expression is a real-valued C language expression over the real values x, y, z, vx, vy, vz, phi, m, t, and the integer value i. [default : 1]
per_weight=t|f
Logical if the result is weight-normalized. [default: t].
tab=t|f
Usually snapinert gives the result in a (barely) human-readable format. This option forces all values printed in one line, so that other programs such as MONGO, TABMATH(NEMO1) and AWK can easily access it. [default: f].

See Also

snapkinem(1NEMO) , snaprect(1NEMO) , bodytrans(3NEMO)

Bugs

From some reasons the source library of the "Numerical Recipes in C" is required to compile snapinert. Since the standard NEMO package does not include the Numerical Recipes, on sites that does not have the sources of Numerical Recipes snapinert cannot be compiled. The Makefile assumes the source library to exist in $NUMRECPATH.

Author

Jun Makino

Update History


30-Jun-88    V1.0: Created    JM
7-jul-89    V1.2: get_snap(), oneline= keyword is now tab=     PJT


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