The program simply outputs eight numbers: time of the first snapshot, are the minimum, lower quartile, median, upper quartile, maximum of the measured differences, and the mean and dispersion of the distribution.

**in1=***snap_file1***in2=***snap_file2*- Input data is read from
*snap_file1*and*snap_file2*, which must be in*snapshot*(5NEMO) format. Default: none. **time1=***time_range1***time2=***time_range2*- Data with time values within
*time_range1*and*time_range2*will be read from*snap_file1*and*snap_file2*, respectively. [Default:**all**]. **obs=***obs_expression**obs_expression*is the observable used to compare the particles. See*bodytrans*(1NEMO) for the form of*obs_expression*. Default:**r**, which compares the positions of particles.**diffpart=***flag*- If
*flag*is true, particles are compared by subtracting the components of one from the components of the other, and evaluating the observable**obs**on this ‘‘differenced particle’’. Otherwise,**obs**is evaluated for each particle, and the results are differenced. Default:**true**. **relative***=flag*- If
*flag*is true, the differenced observable is divided by the value of**obs**computed from the particle in*snap_file1*. Otherwise, the differenced observable is used. Default:**false**. **log=t|f**- Show (10-base) logarithms of the values instead of their linear values Default: false.

src/nbody/reduc/snapcmp.c source code for snapcmp, snapcmphist and snapcmpplot

23-may-88V1.0 created?Josh 29-mar-94V1.3 added time to outputPeter 15-apr-04V1.5 added headline= to the plotting versions and mean,sigma to the outputPJT 16-jul-09V1.6 added log=PJT