Empirical Orthogonal Functions (EOF) homework.

Background reading: Hsieh book chapter 2

1. First, a question about the sense of EOF's:

1. How many values (numbers) are in your input data array? 144 x 240 (lon vs t)
2. How many values (numbers) are needed to build each term on the left? 144 for EOFs, 240 for PCs
3. If 5 EOFs capture most of the data's variance, how much smaller (in the above sense) is the EOFxPC representation compared to the full data set?

2. Read in your field1 (let's call it x again). Use the same data from HW3 data source here.