D Exercise 02

Last updated: 2024-07-28 11:47:09

D.1 Materials

The materials for this exercise are:

• Time series and function definitions (Chapter 3)
• Tables, conditionals and loops (Chapter 4)

D.2 Question 1

• Read the rainfall.csv file into a data.frame object.
• Calculate and print a vector with the station names where at least one of the months has >200 mm of rainfall.

## [1] "Golan Farm" "Eilon"      "Fasutta"    "Yehiam"     "Kfar Mahol"
## [6] "Meron"      "Horashim"

• You can define and use the vector m with month names in your code, to subset the columns with monthly rainfall amounts, as shown in Section 4.4.3:

m = c('sep','oct','nov','dec','jan','feb','mar','apr','may')

(50 points)

D.3 Question 2

• Create the value and time vectors representing the Kinneret water level time series in November and May during 1991-2011, using the expressions from Section 3.1.3
• Calculate the consecutive differences between the current time and the previous one (i.e., water level change in the last 6-months)
• Plot the two separate time series of 6-month differences in November and in May (i.e., the rises in water level over winter, and the drops in water level over summer) (Figure D.1)
• Add a horizontal line marking \(y=0\) (Figure D.1)
• Add text labels marking the location and value of the minimum and maximum differences (i.e., the two most extreme water level changes) (Figure D.1)
• Don’t type any specific values such as 25, 36, 4.6, -2.05, '2008-11-15', and '2003-05-15' in your code! Use the right expressions to calculate them.

Figure D.1: Water level change of lake Kinneret in May and November over time

(50 points)