Code covered by the BSD License  

Highlights from
Closest Approach Between the Earth and Heliocentric Objects

Closest Approach Between the Earth and Heliocentric Objects

by

David Eagle

 

06 Dec 2012 (Updated )

MATLAB script that predicts closest approach between the Earth and heliocentric objects.

atan3 (a, b)
function y = atan3 (a, b)

% four quadrant inverse tangent

% input

%  a = sine of angle
%  b = cosine of angle

% output

%  y = angle (radians; 0 =< c <= 2 * pi)

% Celestial Computing with MATLAB

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

epsilon = 0.0000000001;

pidiv2 = 0.5 * pi;

if (abs(a) < epsilon)
   y = (1 - sign(b)) * pidiv2;
   return;
else
   c = (2 - sign(a)) * pidiv2;
end

if (abs(b) < epsilon)
   y = c;
   return;
else
   y = c + sign(a) * sign(b) * (abs(atan(a / b)) - pidiv2);
end

Contact us