Temperature: the web page to understand what the data set is that you are about to download and work with. Scroll down and click on "The Monthly Global (land and ocean combined into an anomaly) Index (degrees C)". Save the ?le to your computer. The data columns contain year, month, temperature anomaly index. Code: Open a script assign1.m. Write a line of code to load the data ?le using load and assign it to a variable A. Write a (very short!) function gettemp that will take as input A and return as output a structure temp that has four ?elds - temp.year containing the year, temp.month containing the month, temp.time containing time in decimal years (i.e., convert year, month into a decimal year so that e.g., March 1950 is 1950.25) and temp.data containing the temperature anomaly index. The function call in your main script assign1.m should be temp = gettemp(A);

The function is so short it seems unnecessary but you will see as we progress that writing several short functions makes your script assign1.m much easier to read. 2. CO₂: Scroll down to the "Flask CO₂ and Isotopic Data", select "Mauna Loa Observatory, Hawaii", click on "Monthly CO₂" and save the .csv ?le to your computer.

Download the piece of code getco2.m from the class website. The code is almost (not quite!) a function to read the CO2 data ?le and return a structure co2 that, like temp has four ?elds - co₂.year containing the year, co2.month containing the month, co2.time containing the time in decimal years, and co2.data containing the raw monthly CO₂ data (column 5 of the .csv ?le). Add additional code to getco2.m that sets up the structure co₂.

The following lines of code in assign1.m will open and close the co₂ ?les and call the getco2.m function.

fid=fopen('monthly_mlf.csv');
co2 = getco2(fid);
fclose(fid);