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  dis-
	      tribution,  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 distribution is  zero
       (i.e.,  the  distribution  is centered at zero). The standard deviation
       (second parameter) is naturally constrained to be positive.


       Output sites are not guaranteed to be contained within the current geo-
       graphic 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_: _$_D_a_t_e_: _2_0_0_3_/_0_3_/_1_6 _1_2_:_2_5_:_1_9 _$



GRASS 5.0							  s.perturb(1)
