Java Applets

**Linear Regression Fitting and Graphing Programs**

**Linefit Script**.
Note: If your browser doesn't run java applets well, then click on:
**Linefit Script**
for a javascript version of linefit. You should be able to run this on your phones.

**Linefit** was written by Cal Poly
Computer Science students **Joel Onofrio** and **Kiet Tran**. Enter
the "x" and "y" values for your data, and the program will plot the data,
find the slope and intercepts. The program will also find the
uncertainties in these values. You can also change which data is used in
the "linear regression fit". Netscape
4.08 or better or IE 4.0 or better is need with this applet.

**Photon Interference Applet**

**photon interference** was written by Cal Poly
students Matt Henderson, Chang Kim and Jason Kang. Just choose the number of
windows (or screens) and use the task bars.

**photon interference applet** was written by Cal Poly
students Brian De Wolf, Vern Jensen and Juan Pastor.

**Oscilloscope Simulator**

**oscope** was written by Cal Poly
students Michael Lee, Benjlyn Lopez and Pascal Huoth. This version
has "sliders" along the axis to allow the user to move the signal
around. Click "randomize" a few times to get a nice signal.
Note, the nice help box.

**Oscilloscope** was written by
Cal Poly students Erik Waibel, James Wong, Devin Smith and Phan Su.
This applet doesn't have sliders, but it works
very well, and is a good version to start with. There is also a help
box.

**oscilloscope** was
written by Cal Poly students Wei Zhao, Mark Soriano and Mihn Truong.
This version was the first to use "sliders" to move the signal around.
It is well written and simple to use.

**RPN Calculator**

**Central Force Program**

**Alkali Energy Level Programs**

**alkali2** was written by the
student group led by **Anh Mach**. It can run with Netscape 3.0 or
better.

**alkali1** was written by the
student group led ty **Xiong (Sean) Lin**. It can run with Netscape
4.5 or better.

**How to use the Alkali Energy Level Programs**

The program calculates the energy levels for the valence electron for the alkali elements. Pick an element from the box. Pick a value of the parameter c (Angstroms). Then click on calculate, and wait for the calculation to finish. First the experimental values of the energy levels (in eV) for the l=0, l=1, and l=2 levels are printed, Then the calculated values are computed and printed. Vary the parameter c (Angstroms) for the best fit to the experimental values.

The program calculated the energy levels as follows: It is assumed that
the valence electron experiences a "mean field" potential, V(r), due to
the nucleus and the other electrons. The potential V(r) is inserted
into the Schroedinger equation, and the code solves Schroedinger's
equation for the bound states. The potential V(r) is taken to be
the sum of a potential due to **a point charge (the nucleus) of magnitude
+Ze** and a screening potential due to the other (Z-1) electrons in the
atom. The screening potential is that due to **a uniformly charged
sphere of radius c and total charge of -(Z-1)e**.

There is a translation of this page into Danish. All links to translations have been removed.