D Exercise 02

Last updated: 2021-03-31 00:29:17

D.1 Question 1

  • Run the following four expressions to load two vectors named year and co2 into memory:
means = aggregate(co2, FUN = mean)
year = as.vector(time(means))
co2 = as.vector(means)
  • The co2 vector contains \(CO_2\) measurements in the atmosphere, in ppm units, during the period 1959-1997. The year vector contains the corresponding years.
  • Calculate a vector of \(CO_2\) differences between consecutive years, that is:
    • \(CO_2\) in 1960 minus \(CO_2\) in 1959
    • \(CO_2\) in 1961 minus \(CO_2\) in 1960
    • and so on…
  • Create a plot (Figure D.1) with lines and points showing the consecutive \(CO_2\) differences as function of time (1960, 1961, etc.), in black
  • The difference in \(CO_2\) concentration between 2020 and 2019 was equal to 2.64. Add a point in red representing that difference to your plot (use a different point shape, such as pch=4).
$CO_2$ over time

Figure D.1: \(CO_2\) over time

(50 points)

D.2 Question 2

  • 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 >180 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)