function B = FOU_CHB(A,direction)
% A - original data in columns
% B - transformed data in columns
% direction - set equal to 1 for nodal to spectral
%             anything else for spectral to physical


[N,~] = size(A);

if direction==1 % physical-to-spectral
    
    A = flipud(A);% TO FOLLOW THETA DIRECTION
    
    F=ifft([A(1:N,:);A(N-1:-1:2,:)]);
            
    B=([F(1,:); 2*F(2:(N-1),:); F(N,:)]);
        
    
    
    
else            % Spectral-to-physical
    
      F=fft([A(1,:); [A(2:N-1,:);2*A(N,:);A(N-1:-1:2,:)]/2]);
      B = real(F(N:-1:1,:));
    
    
end