s.perturb(1)	       Grass User's Manual	     s.perturb(1)



NNAAMMEE
       ss..ppeerrttuurrbb  - Random location perturbations of GRASS sites.
       _(_G_R_A_S_S _S_i_t_e_s _P_r_o_g_r_a_m_)

SSYYNNOOPPSSIISS
       ss..ppeerrttuurrbb
       ss..ppeerrttuurrbb hheellpp
       ss..ppeerrttuurrbb [--qq] iinnppuutt==_n_a_m_e  oouuttppuutt==_n_a_m_e  ddiissttrriibbuuttiioonn==[[_u_n_i_-
       _f_o_r_m|_n_o_r_m_a_l] ppaarraammeetteerrss==_v_a_l_u_e,[_v_a_l_u_e]

DDEESSCCRRIIPPTTIIOONN
       _s_._p_e_r_t_u_r_b  reads  a site list and writes the same list but
       _p_e_r_t_u_r_b_s 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.

OOPPTTIIOONNSS
   FFllaaggss::
       --qq     Quiet. Cut out the chatter.


   PPaarraammeetteerrss::
       iinnppuutt==_n_a_m_e
	      Name of an existing sites file.

       oouuttppuutt==_n_a_m_e
	      Name of output sites file.

       ddiissttrriibbuuttiioonn==[[_u_n_i_f_o_r_m|_n_o_r_m_a_l]
	      Distribution of perturbation.

       ppaarraammeetteerrss==_v_a_l_u_e[_,_v_a_l_u_e]
	      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.


NNOOTTEESS
       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.


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


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

SSEEEE AALLSSOO
       _g_._r_e_g_i_o_n

       _s_._r_a_n_d_o_m

       _s_._u_n_i_v_a_r

       _s_._k_c_v


BBUUGGSS
       Please send all bug fixes and comments to  the  author  or
       the GRASS development team.


AAUUTTHHOORR
       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 _f_2_c

       _L_a_s_t _c_h_a_n_g_e_d_: _$_D_a_t_e_: _2_0_0_2_/_0_1_/_2_5 _0_5_:_4_5_:_3_5 _$



GRASS 5.0					     s.perturb(1)
