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



NNAAMMEE
       dd..rrhhuummbblliinnee   -	Displays  the  rhumbline  joining  two	user-specified
       points, in the active frame on the user's graphics monitor.
       _(_G_R_A_S_S _D_i_s_p_l_a_y _P_r_o_g_r_a_m_)

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

DDEESSCCRRIIPPTTIIOONN
       A rhumbline is a line following a constant angle of the compass	(i.e.,
       a  line	of  constant  direction).   There are 32 points on the compass
       (points are roughly 11 degrees 15 minutes apart).  _d_._r_h_u_m_b_l_i_n_e displays
       the rhumbline joining any two user-specified points in the active frame
       on the user's graphics monitor.	The named  coordinate  locations  must
       fall within the boundaries of the user's current geographic region.


       The  user  can  run  this  program either interactively or non-interac-
       tively.	If the user simply types dd..rrhhuummbblliinnee on the command line with-
       out  specifying	parameter  values, the mouse will be activated and the
       user will be asked to use the mouse to indicate the  two  endpoints  of
       the  rhumbline.	 The  rhumbline  is  then  drawn  in the default color
       (white). The program also outputs the coordinate locations of  the  two
       endpoints  on  the  user's  terminal and the number associated with the
       mouse button depressed by the user in a	format	useful	for  input  to
       other programs.


       Alternately,  the  user	can  specify  the  starting  and ending longi-
       tude/latitude coordinates of the rhumbline and (optionally)  the  color
       in  which  the  rhumbline  will be displayed; in this case, the program
       will run non-interactively.

OOPPTTIIOONNSS
   PPaarraammeetteerrss::
       ccoooorr==_l_o_n_1_,_l_a_t_1_,_l_o_n_2_,_l_a_t_2
	      Starting and ending coordinates of the  rhumblines  to  be  dis-
	      played, given as longitudes and latitudes.

       llccoolloorr==_n_a_m_e
	      Rhumbline color.
	      Options: red, orange, yellow, green, blue, magenta, indigo, vio-
	      let, gray, white, black
	      Default: white


NNOOTTEESS
       This program works only with longitude-latitude data bases.

SSEEEE AALLSSOO
       _d_._g_e_o_d_e_s_i_c

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

       _L_a_s_t _c_h_a_n_g_e_d_: _$_D_a_t_e_: _2_0_0_2_/_0_1_/_2_5 _0_5_:_4_5_:_3_3 _$



GRASS 5.0							d.rhumbline(1)
