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



NNAAMMEE
       ss..kkccvv  -  Randomly  partition sites into test/train sets.  _(_G_R_A_S_S _S_i_t_e_s
       _P_r_o_g_r_a_m_)

SSYYNNOOPPSSIISS
       ss..kkccvv

       ss..kkccvv hheellpp

       ss..kkccvv [--ddqq] kk==vvaalluuee ssiitteess=_n_a_m_e

DDEESSCCRRIIPPTTIIOONN
       _s_._k_c_v  randomly	divides  a  sites  lists  into	_k sets	of  test/train
       data  (for  kk-fold  ccross vvalidation).  Test  partitions  are  mutually
       exclusive.  That  is,  a site will appear in only  one  test  partition
       and  _k_-_1 training  partitions.  The  program  generates	a random point
       using the selected random number generator and then finds  the  closest
       site to it.  This site is removed from the candidate list (meaning that
       it will not be selected for any other test  set)   and  saved   in  the
       first  test  partition file.  This is repeated until enough points have
       been selected for the test partition.  The  number  of	sites	chosen
       for  test partitions depends upon the number of sites available and the
       number of partitions chosen (this number is made as consistent as  pos-
       sible while ensuring that all sites will be chosen  for testing).  This
       process of filling up a test partition is done _k times.

FFllaaggss::
       --dd   Use _d_r_a_n_d_4_8_(_) (default is _r_a_n_d_(_)_)_.

       --qq  Run quietly. Don't report progress.


PPaarraammeetteerrss::
       kk=_v_a_l_u_e		  Positive integer  value  indicating  the  number  of
       partitions.

       ssiitteess=_n_a_m_e	   Name  of  a	sites  file to store random points in.


       Test/train pairs are saved as sites list using _n_a_m_e as a basename. Test
       sites  are saved in _n_a_m_e-test._i while training sites are saved in _n_a_m_e-
       train._i, where _i ranges from zero to _k_.

NNOOTTEESS
       Existing files are silently overwritten.


       An ideal random sites generator will follow a Poisson dis  only	be  as
       random as the  original	sites.	 This  program simply divides sites up
       in a random manner.


       Be  warned  that  random number generation occurs  over	the  intervals
       defined by the current region.


       This program may not work properly with Lat-long data.

SSEEEE AALLSSOO
       _s_._r_a_n_d_o_m and _g_._r_e_g_i_o_n

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

       http://www.geog.uni-hannover.de/grass/

AAUUTTHHOORR
       James Darrell McCauley ,

       when he was at: Agricultural Engineering Purdue University

       _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.kcv(1)
