Oblique Spherical Triangle toolbox : sss(a, b, c) - File Exchange

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Highlights from
Oblique Spherical Triangle toolbox

aaa(A, B, C) AAA gives both solutions to the angle-angle-angle problem, in radians.
aaad(A, B, C) AAAD gives both solutions to the angle-angle-angle problem, in degrees.
aas(A, B, a) AAS gives both solutions to the angle-angle-side problem, in radians.
aasd(A, B, a) AASD gives both solutions to the angle-angle-side problem, in degrees.
acos2(alpha, beta)
acos2d(alpha, beta)
asa(A, B, c) ASA gives both solutions to the angle-side-angle problem, in radians.
asad(A, B, c) ASAD gives both solutions to the angle-side-angle problem, in degrees.
sas(a, C, b) SAS gives both solutions to the side-angle-side problem, in radians.
sasd(a, C, b) SASD gives both solutions to the side-angle-side problem, in degrees.
ssa(a, b, A) SSA gives both solutions to the side-side-angle problem, in radians.
ssad(a, b, A) SSAD gives both solutions to the side-side-angle problem, in degrees.
sss(a, b, c) SSS gives both solutions to the side-side-side problem, in radians.
sssd(a, b, c) SSS gives both solutions to the side-side-side problem, in degrees.
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from Oblique Spherical Triangle toolbox by Rody Oldenhuis
solves the general oblique spherical triangle

sss(a, b, c)

function [A1, B1, C1, A2, B2, C2] = sss(a, b, c)
%SSS   gives both solutions to the side-side-side problem, in radians.
%
%   SSS(a, b, c) results in NaNs for those indices where the existence 
%   condition |pi - a| - |pi - b| <= |pi - c| <= |pi - a| + |pi -b| is not
%   met. 
%
%   See also SSSD.

% Rody P.S. Oldenhuis
% Delft University of Technology
% Last edited: 23/Feb/2009

    % first solution
    A1 = acos2( (cos(a) - cos(b).*cos(c))./(sin(b).*sin(c)), a);
    B1 = acos2( (cos(b) - cos(a).*cos(c))./(sin(a).*sin(c)), b);
    C1 = acos2( (cos(c) - cos(a).*cos(b))./(sin(a).*sin(b)), c);
    
    % second solution
    A2 = 2*pi - A1;
    B2 = 2*pi - B1;
    C2 = 2*pi - C1;
    
    % check constraints
    indices = ( (abs(pi-a) - abs(pi-b)) <= abs(pi-c) <= (abs(pi-a) + abs(pi-b)) );
    A1(indices) = NaN; B1(indices) = NaN; C1(indices) = NaN;
    A2(indices) = NaN; B2(indices) = NaN; C2(indices) = NaN;
    
end

Highlights from Oblique Spherical Triangle toolbox

Highlights from
Oblique Spherical Triangle toolbox