for loops are taking too much time for simulation of my problem. Here I am giving my part of the problem that how can i reduce time consume of for loop. Could anyone help me or edit my code for better performance. the code is running by large time

 %%this is code in which I have created a 729 no. of text files of each tmy_1, 
%%tmy_1....tmy_729, tmz_1, tmz_2...., tmz_729, tjy_1, tjy_2...., tjy_729 and 
%%tjz_1, tjz_2,......, tjz_729. Each text file consist of 2000 element.
 %%then from the each text file the values are stored in tmyxp(1,1,m,n), 
%%tmzxp(1,1,m,n), tjyxp(1,1,m,n), tjzxp(1,1,m,n) in parallel manner. means you can
%%understand from the code. Hence please anyone help me. it's being serious problem
%for me
 % code
steps=20;
N1=zeros(1,steps);
a=zeros(1,steps);
a1=zeros(1,steps);
a2=zeros(1,steps);
a3=zeros(1,steps);
N2=zeros(1,steps);
N3=zeros(1,steps);
N4=zeros(1,steps);

 for i=number_of_time_steps+1:steps
py=0;
py1=0;
py2=0;
py3=0;
for m=1:27
    for n=1:27
        py=py+1;
        textFilename1=['tmy_' num2str(py) '.txt'];        
        fid=fopen(textFilename1,'r');
        N1=fscanf(fid,'%f');
        fclose(fid);
        a=N1(1:steps);
        tmyxp(1,1,m,n)= a(i);

        py1=py1+1;
        textFilename2=['tmz_' num2str(py1) '.txt'];        
        fid=fopen(textFilename2,'r');
        N2=fscanf(fid,'%f');
        fclose(fid);
        a1=N2(1:steps);
        tmzxp(1,1,m,n)= a1(i);

        py2=py2+1;
        textFilename3=['tjy_' num2str(py2) '.txt'];        
        fid=fopen(textFilename3,'r');
        N3=fscanf(fid,'%f');
        fclose(fid);
        a2=N3(1:steps);
        tjyxp(1,1,m,n)= a2(i);

        py3=py3+1;
        textFilename4=['tjz_' num2str(py3) '.txt'];        
        fid=fopen(textFilename4,'r');
        N4=fscanf(fid,'%f');
        fclose(fid);
        a3=N4(1:steps);
        tjzxp(1,1,m,n)= a3(i);

    end
end
end