You are plotting only one point at a time and without having executed a hold on instruction, each call to plot creates a new line object, deleting the previous. So, at most you would have a dot moving across the axis if the marker size were large enough to see it. To observe this, change your present plot() call to
plot(i,temp(1),'markersize',10)
To do this kind of thing you need to use hold on and update the XData,YData arrays instead, or use the new AnimatedLine feature. See
for details and examples.
