=========== *.m files contents

$ cat avg_data.m 
function refl = avg_data(files);
if size(files, 2) == 1
  files = files'
end
sumf = zeros([180,288])
for fname = files
  fi = load(fname)
  fi.data(isnan(fi.data))=0
  sumf = sumf + fi.data
end

sumf = sumf / length(files)

refl = refl_struct(sumf,fi.start_time,fi.stop_time,fi.type)
return

$ cat avg_alb.m 
function alb = avg_alb(refl);
alb = arrayfun(@(x) earthshine(refl, x), 1:360)
return

$ cat earthshine.m 
function alb = earthshine(refl, degrees);
sunWidth = pi/4
satShift = pi - sunWidth
f = degrees * pi/180 - pi / 2 + sunWidth / 2
earthR = 6371 * 1000
satH = 400*1000*1000 + earthR
sunH = 150*1000*1000*1000
sat = [cos(f+satShift)*satH,sin(f+satShift)*satH,0]
sun = [cos(f)*sunH,sin(f)*sunH,0]
a = albedo(sat, sun, refl) % 's' 'p') 
alb = sum(sum(a))
return


=========== Mathlab

>> files = [ "ga050120.mat"
, "ga050209.mat"
, "ga050301.mat"
, "ga050321.mat"
, "ga050410.mat"
, "ga050430.mat"
, "ga050520.mat"
, "ga050609.mat"
, "ga050629.mat"
, "ga050719.mat"
, "ga050808.mat"
, "ga050828.mat"
, "ga050917.mat"
, "ga051007.mat"
, "ga051027.mat"
, "ga051116.mat"
, "ga051206.mat"
, "ga051226.mat"]
>> 
>> files2 = [ 
, "ga050110.mat"
, "ga050130.mat"
, "ga050219.mat"
, "ga050311.mat"
, "ga050331.mat"
, "ga050420.mat"
, "ga050510.mat"
, "ga050530.mat"
, "ga050619.mat"
, "ga050709.mat"
, "ga050729.mat"
, "ga050818.mat"
, "ga050907.mat"
, "ga050927.mat"
, "ga051017.mat"
, "ga051106.mat"
, "ga051126.mat"
, "ga051216.mat"]
>> 
>> refl = avg_data(files)
>> refl2 = avg_data(files2)
>> a = avg_alb(refl)
>> a2 = avg_alb(refl2)
>> 
>> plot(circshift(a,180));
hold on;
plot(circshift(a2,180))