Month: April 2012

  • Import Access Data into Excel (via VB and ADO)

    I had a lot of data in MySql in a rails application, but I moved to Mongo on a new application and wanted to give the client a nice archive of excel files for each client. It has been a long time since I’ve worked with visual basic, but it came back quickly. I was…

  • Get congressional district data to display on d3.js

    I’m trying to get congressional district data to display on d3.js so I can do some cool overlays. The trick is to get matlab to comply.

  • UTAPS: Mark an IDT as complete

    UTAPS is terrible software. I wasted a half hour today going through the source code to figure out how to mark an IDT as complete. I have no idea how folks who don’t understand web codes can navigate this system. Why not include a button? Really?

  • Your key with fingerprint … is not authorized to access heroku with Ubuntu

    This error was pretty hard to solve. I emailed heroku support and they recommended: “”: bq. For git commands to work git needs to use the ssh key associated with that account. It’s probably choosing a key associated with a different account which is causing these permissions errors. You can use a ~/.ssh/config file to…

  • Render CSV in Rails

    First I read the docs at: to understand how FasterCSV is now in the ruby standard library. Then, I set up the following code: This gives me a pretty flexible solution to render csv, but I’m really interested to see if this is a good way to go. Your comments are appreciated.

  • Radar parameter estimation

    Here we tackle what a Radar needs to accurately measure a target’s position, size and motion. (This is nothing new, just a placeholder for some of my notes.) First of all, everything depends on $SNR$, and the parameter estimation happens in the main computer of a Radar. The theoretical rms error of a measurement is…

  • Wind speed calculation

    I want to know the impact of wind on endurance. So we have something like this: This gives us 8 cases of wind direction: From this we can infer that going to the center from one of the 8 directions. So an overall flight path would look like this: If each grid cell is a…

  • Buyback military years

    h2. Should I even buy the years? what if we use the 13K for something really special? the cashflow is way out there. 1 36 7836.4409 2 37 8692.4214 3 38 9592.7079 4 39 10539.1884 5 40 11533.8243 6 41 12578.6531 7 42 13675.7911 8 43 14827.4367 9 44 16035.8728 10 45 17303.4704 11 46…

  • Resource Allocation with Approximate Dynamic Programming

    [ E = frac{eta}{c}left( frac{C_L^{3/2}}{C_D} right) sqrt{2 rho S} left( frac{1}{W_f} – frac{1}{W_i} right) ] Where (eta) is the propeller efficiency, (c) is the minimum power specific fuel consumption rate, maximum density of air, ( rho ).

  • Winds around the world

    Goal: characterize the winds available around the world. First we need to construct our grid: The horizontal, latitude-longitude grid ranges from +70 to -70 deg in latitude and from 0 to 357.5E deg in longitude, producing a grid that has dimensions of 57 x 144 points. In matlab, this is: [cells/degree northern_latitude_limit western_longitude_limit] zerom( These…