University of Alaska Fairbanks
Geophysical Institute

Beyond the Mouse 2010 - The geoscientist's computational chest.

Lab 1: Thinking Programs / Organizing your Ideas

Exercise 0: Password exchange

You all should have your password by now. If not, talk to Chris Wyatt immediately.

Exercise I: Drawing flow charts

Many of you sent a description of a project they have in mind for this class. Jeff and I responded asking you to think ``big picture'': to identify manageable sub-units and link them together in a meaningful way. Here we want you to continue this process and visualize the result in the form of a flow chart. We recommend to hand draw this as that's faster, things change a lot and it doesn't need to be pretty. Just deliver something that's legible and easy to follow (pre-defined flow chart symbols, give definitions for other symbols)

-- OR --

If you did not figure out a project yet, DON'T PANIC!. Try to create a flow chart for the process of writing and publishing a scientific paper. Understanding this process will certainly be useful at some point in your career as a grad student. You can find inspiration on the web:

• wikipedia, academic publishing: Find the important sections
• Although intended for Biologists, this strategy for writing up research which is part of a Scientific Writing Guide might help.
• if you don't like the links given here, use a search engine of your choice and get your own inspiration

If you've already written and published a paper you will have an easier time, I suppose. You're welcome to give more details. In case branches of your flowchart explode in great detail, consider to lump these things together. Put them on a separate little flow chart and refer to this from the main chart by including a descriptive name there and on the little chart.

Exercise II: Playing with Code -- Learn to swim in the open waters.

Here, we do not care a bit about your programming experience. We want you to familiarize yourself with the MATLAB environment and get you to start playing around. During this process you will hopefully understand the setup of the environment and get a feeling for how MATLAB tries to help you in moments of distress (Hint: Read the red output!).

Hint: If you want to learn more about the MATLAB commands, type doc COMMAND or help COMMAND in the command window.

We want you to document some of your experiences in a textfile. Open notepad; save the file as deepwater.txt and send it to ronni <at> gi <dot> alaska <dot> edu

• Download the examples to your personal space on nugget. (You might want to create a meaningful directory structure along the way.)
• Unpack the examples. You should find the following files: eat.m, getUp.m, haveLife.m, make_my_day.m, screw2d.m, screw2d_bad.m, sleep.m, walk.m, work.m We will not care too much about the screw* files.
• Start MATLAB
• cd to the directory that contains the example files (we'll explain that)
• type: edit make_my_day.m; an Editor Window opens - you will now change the file.
• Suggestions:
  • change the order of the lines
  • delete stuff / add stuff / add '%' in places
  • change the parameters (stuff in parenthesis and single quotes)
  • REQUESTED: change eat to feed_me
• Re-run the script after every change, document the change, and the respective result
• Go to the MATLAB prompt and type: edit eat.m, Save the file as feed_me.m, also change the name of the function to feed_me (Notice the orange box go away), run the script. What happens?
• Now change feed_me.m
• Suggestions:
  • change the number in the pause call.
  • change the string inside the fprintf call.
  • remove the first %s - What happens in the output?
  • remove the mfilename - See a connection?
• Look at some of the other files and play with them. By now you should be getting the hang of it.