%%************************【FCME检测算法函数】****************************%%
%%=============================参数说明===================================%%
% data 待检测的频域信号
% Pf 虚警概率
% J 检测出来的干扰点集合
%%========================================================================%%
function J = FCME(data,Pf)
    T = sqrt(-1*(4/pi)*log(Pf));                                                 %%门限因子
    J = [];
    L = length(data);
    fi = [];
    [y_sort,index] = sort(abs(data),'ascend');                                   %%按幅度值升序排列
    %%求每个频点的幅值
    for k = 1:L
        fi(k)=abs(data(k));
    end
    %%%%初始化两个集合
    J = index(round(L/10)+1:end);                                                %%剩余有干扰集合 
    I = index(1:round(L/10));                                                    %%无干扰集合\
    S = mean(fi(I));
    %%迭代求出干扰点集合
    for m = 1:50                                                                 %%FCME迭代次数
        length_J = length(J);                                                    %%J集合的长度
        ii = 1;
        jj = 1;
        new_I = [];
        new_J = [];
        for j1 = 1:length_J                                                      
             J1 = J(j1);                                                         %%J集合的索引
             if fi(J1) < T*S                                                     %%如果小于门限，则移到I集合，从J集合剔除
                 new_I(ii) = J1; 
                 ii = ii +1;
             else                                                                %%如果大于于门限，则继续留在J集合
                 new_J(jj) = J1;
                 jj = jj + 1;
             end
        end
        if isempty(new_I)                                                        %%如果new_I为空，直接跳出
           break;
        end
        J =  new_J;  
        I = union(I,new_I);
        S = mean(fi(I));                                                         %%干扰频点
    end
end