; $Id: pos.pro,v 1.1 1997/11/14 17:26:52 shyong Exp $
; Demonstrate use the call_external on HP with SPICE library
;
; ispiceinit: load the kernels
; s = call_external('spice.so', 'ispiceinit', kfile);
;   input:
;     string kfile   (kernels file)
; 
; inmetet: MET to ET conversion
; s = call_external('spice.so', 'inmetet', sc, met, num, et);
;   input:
;     long          sc  (spacecraft id)
;     double array  met
;     int           num (number of elements in met)
;   output:
;     double array  et
;
; inposvel: get ephemeris
; s = call_external('spice.so', 'inposvel', target, et, num, states);
;   input:
;     long          target
;     double array  et 
;     int           num     (number of elements in et)
;   output:
;     double matrix states  (target's ephemeris)
;
; inmetquat: get attitude
; s = call_external('spice.so', 'inmetquat', inst, met, num, tol, quat, av);
;   input:
;     long          inst   (instrument's id)
;     double array  met
;     int           num    (number of elements in met)
;     double        tol    (tolerance)
;     double matrix quat   (quaternion)
;     double matrix av     (angular rate)

pro pos

; load kernels
s=call_external('spice.so', 'ispiceinit', 'kernels');

near  = -93L;
nearinst = -93000L;
moon     = 301L;
earth    = 399L;
sun      =  10L;
eros     = 2000433L;
mathilde = 2000253L;

met = [42836264D0, 42836268D0];
et = MAKE_ARRAY(1, 2, /double);

s=call_external('spice.so', 'inmetet', near, met, 2, et);
print, 'ET=', et;

states = MAKE_ARRAY(6, 2, /double);
quats = MAKE_ARRAY(4, 2, /double);
avs = MAKE_ARRAY(3, 2, /double);

s=call_external('spice.so', 'inposvel', near, et, 2, states)
print, 'NEAR position/Velocity:';
print, states

s=call_external('spice.so', 'inposvel', earth, et, 2, states)
print, 'EARTH position/Velocity:';
print, states

s=call_external('spice.so', 'inmetquat', nearinst, met, 2, 1.0D0, quats, avs);
print, 'Quaternion:';
print, quats;

print, 'Angular Velocity:';
print, avs;
end