#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"))