Homework Assignment 1.
Please email your solutions back to Doug Nychka
nychka@ucar.edu by 12PM on Wednesday. It is OK to ask
questions in class about the hoemwork the day it is due.
1) For the PliotSUV dataset use a scatterplot or another type of
plot (e.g. boxplot) to illustrate the relationship between the
asking price and other variables reatled tothe vehicle.
Comment: You can use the text function to label points in a scatterplot
according to other variables. You can use the points to change the
color of the points to indciate different variables. See the very last
example in Rintro3Plotting.pdf
2) For the VictoriaT dataset (monthly temperatures for Lake Victoria.
a) Use the apply function on the component Z to find the mean temperature
over period of the data. Make an image plot of your result.
Comment: See the example(s) in the class notes Rintro6Images.pdf and
Rintro7Apply.pdf
b) Make a simliar figure to indicate the percentage of missing values
that are in each grid box of the data set.
Comment: NA is the missing value code in R.
e.g. hold<- c( 1,2,NA,4) third value of hold is missing (not available)
is.na is a function that gives TRUE or FALSE whether a value is
missing. is.na( hold) would give FALSE, FALSE, TRUE and FALSE
Arithmetic operations used on logical values convert to them to 1 and
0. e.g. sum( is.na( hold) ) gives 1 mean( is.na(hold)) gives .25.