RBF_func.m

function fai = RBF_func(rn, r0, basis)
%% È«¾Ö»ùº¯Êý
if basis == 11          %% Volume Spline
    fai = rn;
elseif basis == 12      %% Thin Plate Spline
    fai = rn^2 * log10(rn); 
elseif basis == 13      %% Multi-Quadric
    c=1e-4;
    fai = sqrt(c^2 + rn^2);
elseif basis == 14      %% Inverse Multi-Quadric
    c=1e-4;
    fai = sqrt(c^2 + rn^2);
    fai = 1.0 / fai;           
elseif basis == 15      %% Inverse Quadric
    fai = 1.0 / (1 + rn^2);    
else                    %% ½ôÖ§»ùº¯Êý
    ksi = rn / r0;
    if ksi >= 1
        fai = 0.0;
    else
        if basis == 21      %% Wendland's C0
            fai = ( 1 - ksi )^2;
        elseif basis == 22  %% Wendland's C2
            fai = ( 1 - ksi )^4 * ( 4.0 * ksi + 1 );
        elseif basis == 23  %% Wendland's C4
            fai = ( 1 - ksi )^6 * ( 35.0 * ksi^2 + 18.0 * ksi + 3 );
        elseif basis == 24  %% Wendland's C6
            fai = ( 1 - ksi )^8 * ( 32.0 * ksi^3 + 25.0 * ksi^2 + 8.0 * ksi + 1 );
        elseif basis == 31  %% compact TPS C0
            fai = ( 1 - ksi )^5;
        elseif basis == 32  %% compact TPS C1
            fai = 3 + 80 * ksi^2 - 120 * ksi^3 + 45 * ksi^4 - 8 * ksi^5 + 60 * ksi^2 * log(ksi);
        elseif basis == 33  %% compact TPS C2a
            fai = 1 - 30 * ksi^2 - 10 * ksi^3 + 45 * ksi^4 - 6 * ksi^5 - 60 * ksi^3 * log(ksi);
        elseif basis == 34  %% compact TPS C2b
            fai = 1 - 20 * ksi^2 + 80 * ksi^3 - 45 * ksi^4 - 16 * ksi^5 + 60 * ksi^4 * log(ksi);
        end
    end
end