## Some applets

Well, currently only one applet...

### Embedding a 2D metric in 3D Euclidean space

The following applet tries to embed a 2D metric in a 3D Euclidean space. More specifically, the 2D metric is of the following type:

*dS ^{2} = dθ^{2}+f(θ)^{2}dφ^{2} *.

The applet lets you embed such a surface in a three-dimensional
Euclidean space for different kinds of *f(θ)* definitions. Note that
in the applet, the variable *x* is used instead of *θ* and that
mathematical functions use the Java syntax: for example, use *Math.sin(x)*
instead of *sin(x)*.

Some interesting expressions to try are:

*Math.sin(x)*(1-0.75*Math.sin(x)*Math.sin(x))*: this will draw a peanut-shaped surface (this is the default setting)*Math.sin(x)*: this draws a sphere*Math.sin(x)*(1+0.1*Math.sin(x)*Math.sin(x))**0.8*Math.sin(x)-0.1*Math.sin(x*2)*

### Spring pendulum

### Governor