nxp = 100;
time_table=zeros(nxp,2);

for ixp=1:nxp
  n=1000;
  k=100;
  m=1;

  x=randn(n,m);

  tic
  tmp = reshape(x,k,[],m);
  x_avg = reshape(mean(tmp),[],m);
  t1=toc;

  tic;
  h=floor(n/k);
  y=zeros(h,m);
  for ik=1:h
    tstart = (ik-1)*k+1;
    tstop = ik*k;
    y(ik,:)=mean(x(tstart:tstop,:));
  end
  t2=toc;

  ratio_high=t1/t2;

  n=1000;
  k=100;
  m=randi(10);
  x=randn(n,m);

  tic
  tmp = reshape(x,k,[],m);
  x_avg = reshape(mean(tmp),[],m);
  t1=toc;

  tic;
  h=floor(n/k);
  y=zeros(h,m);
  for ik=1:h
    tstart = (ik-1)*k+1;
    tstop = ik*k;
    y(ik,:)=mean(x(tstart:tstop,:));
  end
  t2=toc;

  ratio_low=t1/t2;

  time_table(ixp,:) = [ratio_high,ratio_low];
endfor

mean(time_table)
[std(time_table(:,1)),std(time_table(:,2))]