Plot not shown in for loop

The plot is not appearing for this simple loop

for i=0:0.01:1
    if i<0.5
        M=1
    elseif i<0.7
        M=0.5
    else
        M=0
    end
    plot(i,M,'LineWidth',2)
    hold on
end

Answer 1

[Torsten]

iter = 0;
for i=0:0.01:1
  iter = iter + 1;
  I(iter) = i;
  if i<0.5
      M(iter)=1
  elseif i<0.7
      M(iter)=0.5
  else
      M(iter)=0
  end
end
plot(I,M,'LineWidth',2)

Answer 2

[Jan]

Exactly. Give Matlab a chance to update the output by inserting the command:

drawnow

inside the loop.

[Mahmoud Abbas]

Still not working :/

It worked when I tried changing the plot command to: plot(i,M,'*') but I want it to draw the piecewise function with clear lines not with asterisk