Two-Dimensional Graphics. Statistics Graphics and Curves in Explicit, Parametric and Polar Coordinates - MATLAB Graphical Programming - page 41

eXerCISe 2-10
represent the graph of the curve whose equation in polar coordinates is as follows: r = 4 (1 + Cos (a)) for a
between 0 and 2 p , (called a cardioid).
to get the graph of Figure 2-14 , representing the cardioid, use the following syntax:
>> a = 0:0.01:2 * pi;
>> r = 4 * (1 + cos (a));
>> polar(a, r)
>> title('CARDIOID')
Figure 2-14.
eXerCISe 2-11
represent the graph of the lemniscate of Bernoulli whose equation is r = 4 (cos (2a) ^(1/2)) for 0 and 2, and the
graph of the spiral of archimedes whose equation is r = 3a, -4 p <a< - 4 p .
the first curve is represented in Figure 2-15 , and is obtained by the following syntax:
>> a = 0:0.01:2 * pi;
>> r = 4 * (cos(2*a).^(1/2));
>> polar(a, r)
>> title(' Lemniscate of Bernoulli ')