ProjectOnSn.m

function X=ProjectOnSn(X)
% Project a set of points onto Sn.
%
% INPUT:
%   - X : N-by-d array of point coordinates, where N is the number of
%         points.
%   
% OUTPUT:
%   - X : N-by-d array of point coordinates such that norm(X(i,:))=1
%
% AUTHOR: Anton Semechko (a.semechko@gmail.com)
%


if ismatrix(X) && isnumeric(X)
    X=bsxfun(@rdivide,X,sqrt(sum(X.^2,2)));
else
    try
        [Tri,X,fmt]=GetMeshData(X);
    catch
        error('Invalid entry for 1st input argument (X)')
    end
    
    X=bsxfun(@rdivide,X,sqrt(sum(X.^2,2)));
    
    if fmt==1
        X=triangulation(Tri,X);
    elseif fmt==2
        X=TriRep(Tri,X); %#ok<*DTRIREP>
    elseif fmt==3
        X={Tri X};
    else
        X=struct('faces',Tri,'vertices',X);
    end
end