SolarSystem App

This link is an attempt to redesign my SolarSystem java applet. As it’s still under construction and numerous changes are made to the code all the time, you will need to clear your browser data and reload the page to make your browser update to the new code. Have fun with it!

Posted in Math, Science, Software | 4 Comments

The Lorenz Attractor

The Lorenz Attractor

This is my effort to display Edward Lorenz’s equations. First I would like to thank a couple of sources. One is the matrix manipulation code designed by Sun Microsystems (now Oracle Corporation). The version I used here is Matrix3D.java, version 1.4 with the date of 98/03/18. Sun’s license allows one to modify and use the code as long as their copyright comment is maintained. The version here is converted to a JavaScript object (but I kept their comment). The other source is the display of the axes in the lower left corner. I got that idea from an old NASA java applet that displayed the Solar System. They used the same Sun Matrix3D code to perform rotations. You can rotate the display with a left-click of your mouse while moving the mouse across the image.

Continue reading
Posted in Math, Science, Software | Comments Off on The Lorenz Attractor

Writing an LR(1) Parser Generator

About twenty-five years ago, I wrote an LALR(1) compiler-compiler loosely based on the syntax in “Principles of Compiler Design” by Aho and Ullman.  I wrote that program using Kernighan and Ritchie’s C language.  A few years later, I tried the more ambitious effort of reprogramming the compiler-compiler in Stroustrup’s C++.   Unfortunately, it wasn’t a very “clean” version of C++.  Although C++ is a powerful OOP-type language, it’s hard to wring out the older C-type constructs.

Continue reading

Posted in Software | Comments Off on Writing an LR(1) Parser Generator

Comparing Model Results with Data

One of the interesting things about the Kiehl and Trenberth 1997 paper is that it’s possible to make a simple climate model based on it.  This diagram (Figure 1) repeats the paper’s classic (and somewhat overused) Fig. 7, but here I’m only using the data values from the paper’s figure.

Data from Kiehl and Trenberth 1997 Fig 7

Figure 1

Continue reading

Posted in Science | 4 Comments

Death Valley Temperature Changes

Years ago (before 2003 and after 1998), I became interested in desert temperatures (specifically Death Valley). One of the predictions of greenhouse theory is that dry regions, like deserts and polar regions, will show the effects of CO2 warming more than other areas. This is because CO2 effects are masked by water vapor, so dry regions are the “canary in the mine” signal of GW. Unfortunately (for AGW), during the hot year of 1998, Death Valley had a cold year–third coldest in fact. I stored my data away and didn’t check Death Valley temperatures until recently. The current data show that 1998 is still a cool year, but something has changed. The temperatures now shown for Death Valley weren’t as I remembered them. So I pulled out my old data and checked. Below is a comparison of these datasets. The first graph is the pre-2003 plot of my saved data. The second plot is the current GISTEMP values. In the third plot, I overlay the two datasets. Apparently Hansen’s been busy “correcting” these temperature values during the last few years. Continue reading

Posted in Science, Science Fiction | Comments Off on Death Valley Temperature Changes

US Housing Starts

Posted in Economics | Comments Off on US Housing Starts

Civilian Work Force

The plot shown here uses data from the U.S. Department of Labor Statistics.  The light blue dots are total civilian labor force, the light green dots are total civilian employed, and the pink dots are the total civilian unemployment rate.  The black dots are the seasonally adjusted total civilian unemployment rate.  The blue, green, and red lines are 12-month running means of the monthly values (the end-points are a problem–of course).  A 12-month running mean seems to do a better job of filtering out the month-to-month and season-to-season fluctuations and shows the overall trends better.  The vertical brown lines delineate the November elections of each President within the scope of the graph.  Unemployment rate is a lagging economic indicator.

Posted in Economics | Comments Off on Civilian Work Force

Hello world!

Welcome to WordPress.com. This is your first post. Edit or delete it and start blogging!

Posted in Uncategorized | Comments Off on Hello world!