MAE 127: Problem Set 1

Problem Set 1:  ps1.pdf
Solutions:  ps1_sol.pdf

Want to use an alternative to Matlab? See me to discuss options.
Running a tutorial:  The Mathworks has a good tutorial that will help you get started.
http://www.mathworks.com/academia/student_center/tutorials/launchpad.html

If you have used Matlab before, you might check out an alternative tutorial or help page to refresh your knowledge:
Finding help:  To find more details on any matlab function, you can always type help and the name of the function.  Matlab's web site also offers extensive guidance:  http://www.mathworks.com/support/product/product.html?product=ML



Data:  For this problem set, you'll look at temperature data from a buoy in the Santa Monica Basin.   I've prepared a MAT file containing 5 years of historical meteorological data:  buoy.mat.  or for Matlab version 6 buoy_v6.mat 

The MAT file contains seventeen variables, corresponding to the 17 different parameters in the data files.  In this table, the first column identifies the variable name used in the data center files, the second column is the variable name that I've put in the MAT file, and the third column describes the data.
YYYY year Year of observation.
MM month Month of observation.
DD day Date of observation. Note that there are gaps in the data records, so you should convert date and time to a time variable without gaps. The Matlab function datenum can help you with this.
hh hour Time of observation.
ATMP air_temperature Air temperature (Celsius).  Missing data are flagged with 999.  In your analysis, you'll probably want to replace missing values with NaN.
WTMP water_temperature Sea surface temperature (Celsius).  Missing data are flagged with 999.  In your analysis, you'll probably want to replace missing values with NaN.
DEWP dew_point Dewpoint temperature taken at the same height as the air temperature measurement.
PRES atmos_press Sea level pressure (hPa).
WSPD wind_speed Wind speed (m/s) averaged over an eight-minute period. Reported Hourly. Missing data are flagged 99.
WDIR wind_direction Wind direction (the direction the wind is coming from in degrees clockwise from true N) during the same period used for WSPD. Missing data are flagged 999.
GST gust Peak 5 or 8 second gust speed (m/s) measured during the eight-minute period.
WVHT wvht Significant wave height (meters) is calculated as the average of the highest one-third of all of the wave heights during the 20-minute sampling period.
APD apd Average wave period (seconds) of all waves during the 20-minute period.
DPD dpd Dominant wave period (seconds) is the period with the maximum wave energy.
MWD mwd Mean wave direction corresponding to energy of the dominant period (DOMPD). The units are degrees from true North just like wind direction.
VIS visibility Station visibility (statute miles).
TIDE tide The water level in feet above or below Mean Lower Low Water (MLLW).


The data come from the National Data Buoy Center and are described in detail on this web page:
http://www.ndbc.noaa.gov/station_history.php?station=46025
Data were collected from a buoy at the circled location:
southwest buoy map
The buoy looks something like this:
buoy image