Inkscape

Start t-value: -3.1
End t-value: 31.4
Multiply t-range by 2*pi: No
x-value of rectangle's left: -10
x-value of rectangle's right: 10
y-value of rectangle's bottom: -10
y-value of rectangle's top: 10
Samples: 200
x function: t+cost(3*t)
y function: 3*sint(3*t)

Start t-value: -3.1
End t-value: 314
Multiply t-range by 2*pi;: No
x-value of rectangle's left: -10
x-value of rectangle's right: 10
y-value of rectangle's bottom: -10
y-value of rectangle's top: 10
Samples: 200
x function: t+cost(0.15*t)
y function: 15*sin(0.15*t)