#first import your two data sets and save as a named "dataframe"
#They should be saved in your Working Directory with a short, meaningful file name

NYBG_SP1 <- read.csv("zizia_sampleData.csv") #you can re-name the left hand ("NYBG_SP1") to whatever you want, but you will have to change all of the following code as well.
                                  #The part if quotations should be your file name

NYBG_SP2 <- read.csv("alliaria_sampleData.csv") #you can re-name the left hand ("NYBG_SP1") to whatever you want, but you will have to change all of the following code as well.
                                     #The part if quotations should be your file name


#Now, do a bit of investigating for the years represented in your data

length(na.omit(NYBG_SP1$year)) #This will give you the number of rows that contain a value; e.g., your sample size

summary(NYBG_SP1$year) #This will report the lowest, median, mean, and maximum values for the varaible "year" within the dataframe "NYBG_SP1"

#Figure out how many decades are represented in your data
  #(Max - Min)/10 = number of decades
  #Use this for the "breaks" below

#make a histogram of specimen collection years for each species

h <- hist(NYBG_SP1$year,
     main = "Title",         #Replace "title" with a meaningful header for your figure
     xlab = "x-axis label",  #Replace "x-axis label" with an appropriate x-axis label
     xlim = c(1800,2020),    #Replace these numbers with your min and max years
     ylim = c(0, 20),        #You'll come back to this
     breaks = 17)            #Experiment with this number, perhaps replace this numbers with your number of represented decades

#Select and run everything within "h <- hist(...)"

#Figure out how many observations are in the largest category

h$counts  #output is a list of the number of observations within each category
          #In the output, find the largest number.
          #Go back to the above histogram code, and alter the ylim parameter to fit your tallest bar

#Re-run the histogram code with your altered y-axis limits

#Add labels to your histogram

text(h$mids, h$counts, labels = h$counts, adj = c(0.5, -0.5))

#Export your histogram as an image for use in your report

#Repeat the above with your second species: Change every instance of "NYBG_SP1" to "NYBG_SP2" 
#Then, use these representations of the data (two histograms) to answer your research question.