function [data,label,task_index,ins_num]=PreprocessMTData(data,label)

    m=length(data);

    newdata=[];

    newlabel=[];

    task_index=[];

    ins_num=zeros(1,m);

    for i=1:m

        newdata=[newdata;data{i}];

        newlabel=[newlabel,label{i}];

        task_index=[task_index,i*ones(1,size(data{i},1))];

        ins_num(i)=size(data{i},1);

    end

    clear data label;

    data=newdata;

    label=newlabel;

    clear newdata newlabel;