r.median(1)		      Grass User's Manual		   r.median(1)



NNAAMMEE
       rr..mmeeddiiaann   -  Finds  the  median  of values in a cover map within areas
       assigned the same category value in a user-specified base map.
       _(_G_R_A_S_S _R_a_s_t_e_r _P_r_o_g_r_a_m_)

SSYYNNOOPPSSIISS
       rr..mmeeddiiaann
       rr..mmeeddiiaann hheellpp
       rr..mmeeddiiaann bbaassee==_n_a_m_e ccoovveerr==_n_a_m_e oouuttppuutt==_n_a_m_e

DDEESSCCRRIIPPTTIIOONN
       _r_._m_e_d_i_a_n calculates the median category of data contained  in  a  ccoovveerr
       raster  map  layer  for	areas  assigned the same category value in the
       user-specified bbaassee raster map layer.  These median values  are	stored
       in the new oouuttppuutt map layer.


       The oouuttppuutt map is actually a _r_e_c_l_a_s_s of the bbaassee map.

OOPPTTIIOONNSS
       If  the	user  simply  types  rr..mmeeddiiaann on the command line, the user is
       prompted for the parameter values through the  standard	_p_a_r_s_e_r	inter-
       face.


       Alternately,  the  user	can  supply all needed parameter values on the
       command line.

   PPaarraammeetteerrss::
       bbaassee==_n_a_m_e
	      An existing raster map layer in the user's current mapset search
	      path.   For each group of cells assigned the same category value
	      in the bbaassee map, the median of the values assigned  these  cells
	      in the ccoovveerr map will be computed.

       ccoovveerr==_n_a_m_e
	      An existing raster map layer containing the values to be used to
	      compute the median within each category of the bbaassee map.

       oouuttppuutt==_n_a_m_e
	      The name of a new map layer to contain program output (a _r_e_c_l_a_s_s
	      of  the bbaassee map).  The median values will be stored in the oouutt--
	      ppuutt map.


NNOOTTEESS
       The user should use the results of  _r_._m_e_d_i_a_n  with  care.   Since  this
       utility	assigns a value to each cell which is based on global informa-
       tion (i.e., information at spatial locations other than just the  loca-
       tion  of the cell itself), the resultant map layer is only valid if the
       geographic region and mask settings are the same as they  were  at  the
       time that the result map was created.


       Results are affected by the current region settings and mask.

SSEEEE AALLSSOO
       _g_._r_e_g_i_o_n _r_._a_v_e_r_a_g_e _r_._c_a_t_s _r_._c_l_u_m_p _r_._d_e_s_c_r_i_b_e _r_._m_a_p_c_a_l_c _r_._m_a_s_k _r_._m_f_i_l_t_e_r
       _r_._m_o_d_e _r_._n_e_i_g_h_b_o_r_s _r_._r_e_c_l_a_s_s _r_._s_t_a_t_s _p_a_r_s_e_r

AAUUTTHHOORR
       Michael Shapiro, U.S.Army Construction Engineering Research Laboratory

       _L_a_s_t _c_h_a_n_g_e_d_: _$_D_a_t_e_: _2_0_0_2_/_0_1_/_2_5 _0_5_:_4_5_:_3_4 _$



GRASS 5.0							   r.median(1)
