### Riemann Sums

Lets the user enter a function, and adjust the parameters for various left/right/midpoint Riemann sums.

Some programs I have written for use while teaching introductory calculus courses.

Lets the user enter a function, and adjust the parameters for various left/right/midpoint Riemann sums.

The user may enter a function and visualize the disks-and-washers decomposition of its volume of revolution.

The user may enter a function and visualize the cylindrical shells decomposition of its volume of revolution.

Some programs I have written for introducing parametric equations and fields.

Some programs potentially useful in teaching Differential Geometry.

Numerically solving the geodesic equation for the metric on the graph of $\exp(-x^2-y^2)$ from $\mathbb{R}^3$.

Solving the geodesic equation on a torus of revolution in $\mathbb{R}^3$ with the induced metric. Adjust the initial location and direction to explore the positively curved exterior, negatively curved interior, and the effect of the umbilic points.

The geodesic ball based at a $p$ of radius $r$ is the set of all points which can be connected to $p$ by a geodesic of length at most $r$. Its boundary, the set of points connected to $p$ by a goedesic of length exactly $r$, is a geodesic circle. The Gaussian curvature of a surface can be defined by studying the length of these circles as a function of $r$, as $r$ tends to 0.

The Gaussian curvature of a surface in $\mathbb{R}^3$ at a point $p$ is the product of the two principal curvatures at that point. This program takes advantage of the existence of a relatively simple formula for this curvature on the graph of a 2-variable function to color the surface via its curvature (red=positive, blue=negative) in real time.

A conformal map is one that preserves angles, but may distort distances. This program gives some examples of distance-distorting conformal maps through visualizing conformal embeddings of the Euclidean square torus into $\mathbb{R}^3$. These embeddings come via composing an isometric embedding into $\mathbb{S}^3$ with stereographic projection.

Some programs from teaching Hyperbolic Geometry.

A path in the 3-dimensional subspace of deformation space of a genus 2 surface with zero twist parameter, which approaches the boundary by almost pinching a curve.

Some programs from teaching complex analysis.

A depiction of the graph of $z\mapsto \exp(z)$ in $\mathbb{C}^2$ projected to $\mathbb{R}^3$ via orthogonal projection with respect to some (time varying) axis.

A depiction of the graph of $z\mapsto z^n$ in $\mathbb{C}^2$ projected to $\mathbb{R}^3$ via orthogonal projection with respect to some (time varying) axis. The grid represents polar coordinates on the domain, the hues represent polar coordinates on the codomain.

Some programs from teaching analysis.

In some sense the precursor to sinusoidal expansions, this Greek geocentric cosmological system successfully modeled non-circular motion as a sum of two circular motions.

Some programs from introductory PDEs.

Sliders allowing you to move about within a finite dimensional subspace of sinsusoidal soltuions.

Numerics for a gaussian wavepacket confined to a rectangular domain.

Some programs for single-particle quantum mechanics.

Numerically solving the Schrodinger equation for a gaussian wavepacket moving towards a pair of slits in an infinite potential wall.

Numerically solving the Schrodinger for a free particle confined to an elliptical domain.

Solving the Schrodinger equation for a wave packet moving towards a finite potential barrier.