GNU.WIKI: The GNU/Linux Knowledge Base

  [HOME] [PHP Manual] [HowTo] [ABS] [MAN1] [MAN2] [MAN3] [MAN4] [MAN5] [MAN6] [MAN7] [MAN8] [MAN9]

  [0-9] [Aa] [Bb] [Cc] [Dd] [Ee] [Ff] [Gg] [Hh] [Ii] [Jj] [Kk] [Ll] [Mm] [Nn] [Oo] [Pp] [Qq] [Rr] [Ss] [Tt] [Uu] [Vv] [Ww] [Xx] [Yy] [Zz]


NAME

       v.perturb  - Random location perturbations of GRASS vector points

KEYWORDS

       vector, geometry, statistics

SYNOPSIS

       v.perturb
       v.perturb help
       v.perturb    [-q]    input=name    output=name    [distribution=string]
       parameters=float[,float,...]      [minimum=float]        [seed=integer]
       [--overwrite]  [--verbose]  [--quiet]

   Flags:
       -q
           Quiet

       --overwrite
           Allow output files to overwrite existing files

       --verbose
           Verbose module output

       --quiet
           Quiet module output

   Parameters:
       input=name
           Vector points to be spatially perturbed

       output=name
           Name for output vector map

       distribution=string
           Distribution of perturbation
           Options: uniform,normal
           Default: uniform

       parameters=float[,float,...]
           Parameter(s)  of distribution. If the distribution is uniform, only
           one parameter, the maximum, is needed. For a  normal  distribution,
           two parameters, the mean and standard deviation, are required.

       minimum=float
           Minimum deviation in map units
           Default: 0.0

       seed=integer
           Seed for random number generation
           Default: 0

DESCRIPTION

       v.perturb  reads  a vector map of points and writes the same points but
       perturbs the eastings and northings  by  adding  either  a  uniform  or
       normal  delta  value.  Perturbation  means  that  a  variating  spatial
       deviation is added to the coordinates.

NOTES

       The uniform distribution is always centered about zero.  The associated
       parameter  is  constrained  to be positive and specifies the maximum of
       the distribution; the minimum is the negation  of  that  parameter.  Do
       perturb  into  a  ring  around the center, the minimum parameter can be
       used.

       Usually, the mean (first parameter) of the normal distribution is  zero
       (i.e.,  the  distribution  is centered at zero). The standard deviation
       (second parameter) is naturally constrained to be positive.

       Output vector points are not guaranteed  to  be  contained  within  the
       current geographic region.

SEE ALSO

       v.random
       v.univar

AUTHOR

       James Darrell McCauley
       when he was at: Agricultural Engineering Purdue University

       Random  number generators originally written in FORTRAN by Wes Peterson
       and translated to C using f2c.

       Last changed: $Date: 2011-11-08 01:42:51 -0800 (Tue, 08 Nov 2011) $

       Full index

       © 2003-2013 GRASS Development Team



  All copyrights belong to their respective owners. Other content (c) 2014-2018, GNU.WIKI. Please report site errors to webmaster@gnu.wiki.
Page load time: 0.133 seconds. Last modified: November 04 2018 12:49:43.