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snappeak - find peak in each phase space coordinate using a mode analysis


snappeak in=in_file [parameter=value] ...


snappeak finds the peak in the distribution of points in phase space. When the coordinate system is cartesian, the peaks in position actually correspond to the density center.

This method is an application of the general problem of the statistical analysis of a (probablity) distribution function. One can determine the median, position where there is equal chance (half) of being to the left or right, the mean being the averaged position of a distribution function and the mode where the distribution function takes its maximum value (probability). This program computes the maximum peak value of the distribution function in each coordinate independantly.


The following parameters are recognized:
input file, in snapshot(5NEMO) format. Default: none.
The number of particles used in the sliding window of the mode analysis. It is a kind of smoothing parameter. [default: 100].
Only snapshots with time values within times-ranges, which is of the form ts[:te],..., will be copied. [default: all].


This program has not been loaded in the official release of NEMO. If you need it, ask the author for a copy or to add it to NEMO. Better alternatives are snapcenter(1NEMO) , and snapdens(1NEMO)


Peter Teuben

Update History

xx-nov-86    V1.0: original version       Peter Teuben
15-jan-87    V1.0a: improvements    PJT
10-jun-87    V1.0b: some cleanup    PJT
6-jun-88    V1.1: new filestruct    PJT

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