d.geodesic(1)	       Grass User's Manual	    d.geodesic(1)



NNAAMMEE
       dd..ggeeooddeessiicc  - Displays a geodesic line, tracing the short-
       est distance between two geographic points along  a  great
       circle, in a longitude/latitude data set.
       _(_G_R_A_S_S _D_i_s_p_l_a_y _P_r_o_g_r_a_m_)

SSYYNNOOPPSSIISS
       dd..ggeeooddeessiicc
       dd..ggeeooddeessiicc hheellpp
       dd..ggeeooddeessiicc     [ccoooorr==_l_o_n_1_,_l_a_t_1_,_l_o_n_2_,_l_a_t_2]    [llccoolloorr==_n_a_m_e]
       [ttccoolloorr==_n_a_m_e]

DDEESSCCRRIIPPTTIIOONN
       _d_._g_e_o_d_e_s_i_c displays a geodesic line in the active frame on
       the user's graphics monitor. This line traces the shortest
       distance between two user-specified points on  the  curved
       surface of a longitude/latitude data set.  The two coordi-
       nate locations named must fall within  the  boundaries  of
       the user's current geographic region.

OOPPTTIIOONNSS
       This program can be run either interactively or non-inter-
       actively.  If the user types  dd..ggeeooddeessiicc  on  the  command
       line  without  other program parameters, the mouse will be
       activated; the user is asked to use the mouse to  indicate
       the starting and ending points of each geodesic line to be
       drawn. The default line color (white) and text color (red)
       will be used.


       Alternately,  the user can specify the starting and ending
       coordinates of the geodesic, line color, and text color on
       the command line, and run the program non-interactively.


       Once  the  user	indicates the starting and ending coordi-
       nates of the geodesic, the line and its length (in  miles)
       are displayed to the user's graphics monitor.



   PPaarraammeetteerrss::
       ccoooorr==_l_o_n_1_,_l_a_t_1_,_l_o_n_2_,_l_a_t_2
	      Starting	and  ending coordinates, in longitude and
	      latitude values, of the geodesic line to be  drawn.

       llccoolloorr==_n_a_m_e
	      Line color in which geodesic will be displayed.
	      Options: red, orange, yellow, green, blue, magenta,
	      indigo, violet, gray, white, black
	      Default: white

       ttccoolloorr==_n_a_m_e
	      Text color in which the length of the geodesic will
	      be displayed.
	      Options: red, orange, yellow, green, blue, magenta,
	      indigo, violet, gray, white, black.  Default: red


NNOOTTEESS
       This program works only on GRASS data bases using a longi-
       tude/latitude coordinate system.

SSEEEE AALLSSOO
       _d_._r_h_u_m_b_l_i_n_e

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

       _L_a_s_t _c_h_a_n_g_e_d_: _$_D_a_t_e_: _2_0_0_2_/_0_1_/_2_5 _0_5_:_4_5_:_3_2 _$



GRASS 5.0					    d.geodesic(1)
