#This is an example of making bar plots

     #   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
barplot( fn_length )
     #  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
barplot( fn_length )
     #    ***********************************************
     #    ***   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

barplot( fn_length, ylim=c(0,140))

     #  And we should put a title on this graph

barplot( fn_length, ylim=c(0,140),
         main="Length of First Names for Math 160 Students")

     #  And, to make this a bit easier to read
     #  we will add a bottom line and then add some dotted
     #  horizontal lines.
abline(h=0, lty="solid")
abline(h=seq(0, 140, 20), lty="dotted")

     #  With a little planning we could get those lines in 
     #  the background.  First, generate a new graph.
barplot( fn_length, ylim=c(0,140),
         main="Length of First Names for Math 160 Students")
abline(h=0, lty="solid")
abline(h=seq(0, 140, 20), lty="dotted")
     #  Then give this strange command which does seem backwards
     #  but when new is TRUE a new command will write over the
     #  existing plot
par( new=TRUE)
     #  so now just draw the plot again.
barplot( fn_length, ylim=c(0,140),
         main="Length of First Names for Math 160 Students")
par( new=FALSE )
     #
     # We could start over, but this time get a horizontal graph
 
barplot( fn_length, horiz=TRUE,
         main="Length of First Names for Math 160 Students")
     #  This time we should increase the bottom scale
barplot( fn_length, horiz=TRUE, xlim=c(0,140),
         main="Length of First Names for Math 160 Students")
     #  And the names along the left just do not fit because
     #  of their direction with respect to the axis.  We can
     #  change that so that the names are perpendicular to 
     #  the axis
barplot( fn_length, horiz=TRUE, xlim=c(0,140), las=1,
         main="Length of First Names for Math 160 Students")
     #  And we can add some vertical lines
abline( v=0, lty="solid")
abline(v=seq(0,140,20), lty="dotted")
par( new=TRUE)
barplot( fn_length, horiz=TRUE, xlim=c(0,140), las=1,
         main="Length of First Names for Math 160 Students")
     #  And, while we are making this a bit fancier let us
     #  add some ccolor to it
par( new=TRUE )
barplot( fn_length, horiz=TRUE, xlim=c(0,140), las=1,
         main="Length of First Names for Math 160 Students",
         col=rainbow(9))
par( new=FALSE )

#########################################################
#     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 barplot()
      #  functon on L1 but that will not work
barplot(L1)
      #  we have a bar for each value in the data and the 
      #  length (in this case height) of each bar is the 
      #  magnitude of the associated value.

      # but what we want is a bar plot 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.
barplot( table(L1) )
      #  And, we can fancy that up to our heart's content
barplot( table(L1), ylim=c(0,25), 
         main="Frequencies of values in the table",
         col=c("red","green","blue","orange","purple",
               "tan"))
abline(h=0, lty="solid")
abline(h=seq(0,25,5), lty="dotted", col="darkred")
par(new=TRUE)
barplot( table(L1), ylim=c(0,25), 
         main="Frequencies of values in the table",
         col=c("red","green","blue","orange","purple",
               "tan"),
         xlab="Table values.")
par( new=FALSE )