fn = {'2004_312_Sz.txt' '2004_313_Sz.txt' '2004_314_Sz.txt' '2004_315_Sz.txt' ...
      '2005_20_Sz.txt'  '2005_21_Sz.txt'  '2005_22_Sz.txt'  '2005_23_Sz.txt' ...
      '2005_24_Sz.txt'  '2005_148_Sz.txt' '2005_149_Sz.txt' '2005_150_Sz.txt' ...
      '2005_151_Sz.txt' '2005_235_Sz.txt' '2005_236_Sz.txt' '2005_237_Sz.txt' ...
      '2005_252_Sz.txt' '2005_253_Sz.txt' '2005_254_Sz.txt' '2005_255_Sz.txt' ...
      '2005_256_Sz.txt'};

Sz = []; Sz_ind = []; 
Vx = []; Vy = []; Vz = [];
Bx = []; By = []; 
Ex = []; Ey = []; Ez = [];
MLAT = []; MLT = []; 
GLAT = []; GLON = [];
for i = 1:length(fn)
    data = read_Poynting(fn{i});    
    MLAT = [MLAT;data(:,5)'];
    MLT  = [MLT;data(:,6)'];
    GLAT = [GLAT;data(:,7)'];
    GLON = [GLON;data(:,8)'];
    Vx = [Vx;data(:,10)'];
    Vy = [Vy;data(:,11)'];
    Vz = [Vz;data(:,12)'];
    Bx = [Bx;data(:,13)'];
    By = [By;data(:,14)'];
    Ex = [Ex;data(:,17)'];
    Ey = [Ey;data(:,19)'];
    Ez = [Ez;data(:,21)'];
    Sz = [Sz;data(:,23)'];
    Sz_ind = [Sz_ind;data(:,24)'];
end