Try this A=[-0.01342 -0.00200 0.04210 0.01854 0.07183 0.01343 0.07494 0.02699 -0.08492 0.02870 -0.01921 -0.07003 -0.07477 0.03745 -0.03381 0.01330 0.02992 -0.03780 -0.00544 0.04873 -0.00489 -0.01814 0.00560 0.00055]
newCellMean=zeros((numel(A)/3),1);
for i=1:ceil(numel(A)/3)
if i==ceil(numel(A)/3)
newCellMean(i,1)=mean(A((((3*i)-2)):end,1));
else
newCellMean(i,1)=mean(A((((3*i)-2)):(3*i),1));
end
end
