i want to plot a square wave

 this is the main equation f(t)=(4/m*pi)sin(2*pi*m*t) m=1,3,5,7,9

and I need to plot the sum of harmonics against time for a time period between 0 and 10

f(t)=(4/pi)sin(2*pi*t)+(4/3*pi)sin(2*pi*3*t)+(4/5*pi)sin(2*pi*5*t)+(4/7*Pi)sin(2*pi*7*t)

[Walter Roberson]

Duplicates http://uk.mathworks.com/matlabcentral/answers/249146-i-want-to-plot-a-square-wave