#This is an example of making pie charts
# the first plot comes from data given on the
# the background page for the associated video
# We want to get the values that we will plot
# into our script. Use the c() function to
# create our variable holding the values
fn_length <- c( 7, 47, 93, 117, 95, 57,
24, 8, 4)
# then, in its most basic form we can get a plot
pie( fn_length )
# that is a bit smaller than we want so try this
pie(fn_length, radius=1)
# And we can just expand the area of the lower
# right pane in RStudio
pie(fn_length, radius=1)
# of course, it would be nice to get labels on the
# bars. To do this we will assign names to the
# values in our variable fn_length
names(fn_length) <- c("Three", "Four", "Five", "Six",
"Seven", "Eight", "Nine",
"Ten", "over ten")
# and then create a new plot
pie( fn_length, radius=1 )
# ***********************************************
# *** This is as fancy as you need to get ***
# *** for any bar plot reuired in this ***
# *** class. The rest is just showing off. ***
# ***********************************************
# Now I want to extend the vertical scale, To do this
# we mmake our command a bit more complex
pie( fn_length, radius=1, col=rainbow(11))
# And we should put a title on this graph
pie( fn_length, radius=1, col=rainbow(11),
main="Length of First Names for Math 160 Students")
# and, we could change the direction of the slices
pie( fn_length, radius=1, col=rainbow(11),
clockwise=TRUE, init.angle=0,
main="Length of First Names for Math 160 Students")
#########################################################
# Now look at the second problem
#########################################################
# Load gnrnd4 so that we can generate the values
source( "../gnrnd4.R")
# Then run gnrnd4 to actually create the values
gnrnd4(745099103, 600031)
# The values are in L1, inspect them to be sure
# that we have the right values
L1
#
# We might think that we can just use the pie()
# functon on L1 but that will not work
pie(L1)
# we have a slicw for each value in the data
# and the angle for each slice in the pie
# is the relative
# magnitude of the associated value.
# but what we want is a pie chart that shows the frequency
# of each different value in the data. We could try to
# count the number of 35's, the number of 36's, and
# so on, but we will almost certainly make at least one
# mistake. So, let the computer do it for us. The
# function table() will get those frequencies...
table(L1)
# So I see that there are 8 "32's", 21 "33's, and
# so on. Now, I have the same kind of information
# that we had in the first problem. We could do the
# same steps and create a variable that holds the
# frequencies and then plot that variable. But there
# is a shorter way to do this, just give barplot()
# the result of the table() function.
pie( table(L1) )
# And, we can fancy that up to our heart's content
pie( table(L1), radius=1,
main="Frequencies of values in the table",
col=c("red","green","blue","orange","purple",
"tan"))