# coords.maple -- set up and covert between coordinates, gridfn arrays, etc
# $Header$

#
# setup_coords - set up coordinates
#

################################################################################

#
# This function sets up the coordinates.
#
setup_coords :=
proc()
global
  @include "../maple/coords.minc";

N := 3;					# number of spatial coordinates,
					# i.e. spatial coordinate indices
					#      are 1..N
N_ang := 2;				# number of angular spatial coordinates

# Kronecker delta
delta := array(1..N, 1..N, identity);

# (x,y,z) coordinates
# n.b. individual coordinates are (xx,yy,zz) to avoid confusion with
#      local variables x, y, etc
x_xyz := array(1..N);
x_xyz[1] := xx;
x_xyz[2] := yy;
x_xyz[3] := zz;
x_xyz_list := [xx, yy, zz];
x_xyz_set := {xx, yy, zz};

# r coordinate
r__fnd := ssqrt(xx^2 + yy^2 + zz^2);

# (rho,sigma) coordinates
y_rs := array(1..N_ang);
y_rs[1] := rho;
y_rs[2] := sigma;
y_rs_list := [rho, sigma];
y_rs_set := {rho, sigma};

# list of all coordinates (for sorting things into "nice" order)
xy_all_list := [op(x_xyz_list), op(y_rs_list)];
xy_all_set := {op(xy_all_list)};

NULL;
end proc;