Summer project 2006 resource page (for students supervised by R. Caballero)

FAQ

1) How do I get into the data server?
Open a terminal on the computer you're using and do:
ssh -X your.user.name@augie.ucd.ie
For things to work properly, the computer you are connecting from needs to have ssh and an X server installed. If you have no idea what that means, don't worry, just use the machines in the maths computer lab, which will work fine.

2) How do I transfer files to/from the data server?
If you need to transfer a file from your local machine onto the server, do:
scp filename your.user.name@augie.ucd.ie:
Don't forget the : at the end! To transfer a file from the data server to your local machine, do
scp your.user.name@augie.ucd.ie:filename .
Don't forget the . at the end!

3) Where is the data?
The data you will need are in /home/rca/obs/ERA40 and /home/rca/obs/Irish-station-data

4) How do I read the data?
Here are some example python scripts to help you read the data
Read ERA40 data
Read station data
Convert time format between hours-since-1800 (as used by ERA40) and year-month-day-hour

5) How do I plot the data?
The recommended plotting package is matplotlib.pylab. Here are some examples to get you going.

• X-Y plots:
  To plot two same-length 1-d arrays X and Y (eg. time vs. pressure), do
  from pylab import *
  plot(X,Y)
  show()
  You can customize the plot's appearance in various ways, as documented here.
  
  
• Contour plots:
  To display a 2-d array of data as a contour plot, use the contour function defined here.
  Here's a usage example (which assumes the contour function is already defined higher up in the script):
  ...
  contour(lon,lat,x)
  show()
  

6) How do I compute a trend?
A linear trend is the straight line y = a + b*x that best fits a string of data.
Here is a python function that computes a linear trend. It returns the value of b. It accepts 1, 2 or 3D arrays, and returns the trend along the 1st dimension.

Project specifications and meeting times

• Luis Wed 10.30 am
• Qian Mon 10.30 am
• Liz W. Wed 10 am
• Hamid Wed 11 am
• Liz C. Mon 10 am
• Brenda Mon 11 am