Matlab 2011a优于2015b

Question

我在matlab中有一个非常奇怪的时差。以下代码（我知道它有点乱）在matlab 2011a上运行得非常快（每次迭代的平均时间为2.5秒），而在matlab 2015b上它平均需要25秒！任何建议为什么会发生这种情况？如果我能在matlab 2015b中得到这个时间，那将会很方便。

for k = 1:length(z),
      tic;  
      file = z(k).name; 
      sep = fopen([pathf filesep file],'r');
  frewind(sep)
  icc = 1;
  illt=1;
  data = [];
  while 1
    h = fgetl(sep);

    if illt==10  
        LAT(k)=str2num(h(19:20)) + str2num(h(22:26))/60;
    elseif illt==11
        LON(k)=- (str2num(h(20:22)) + str2num(h(24:28))/60);
    elseif illt==12
        TIME(k)=datenum(h(21:40));
    end
    if ~ischar(h), break; 
    end
    if numel(h)==0 || strcmp(h(1),'#') || strcmp(h(1),'*')
        illt=illt+1;
    else
      data(icc,:) = str2num(h);
      icc = icc+1;
    end
  end

  [mm nn]=size(data);
  iq0 = find(diff(data(:,4)) <=0);

  iq=iq0;


  q=1;
  while data(q,4)<6 ,  q=q+1; end
  position=q;
  c=1;
  for qq=position:iq
  TEMP1(c,k)=data(qq,2);
  COND1(c,k)=data(qq,3);
  PRESS1(c,k)=data(qq,4);
  OOO1(c,k)=data(qq,16);     
  PTEMP1(c,k)=data(qq,9);
  PTEMP2(c,k)=data(qq,19);
  SALIN1(c,k)=data(qq,8);
  SALIN2(c,k)=data(qq,20);
  PDEN1(c,k)=data(qq,15); % sigma-theta, pot. density...
  % with effect of adiabatic cooling/heating effect...
  %[using potential temperature] and the pressure effect removed
  PDEN2(c,k)=data(qq,17);  % sigma-t, pot. density at atm. pressure
  c=c+1;
  end
toc;
end