CSC 343: The Week beginning Oct. 22

• Homework:
  
  Watch and summarize the following videos
  JavaScript Let vs Var vs Constant
  JavaScript this Keyword
  
  Make a page with an slideshow. You can follow the example at https://www.w3schools.com/howto/howto_js_slideshow.asp
  
  Make a page with a model box. You can follow the example at https://www.w3schools.com/howto/howto_css_modals.asp
  
  Make a page with a model image. You can follow the example at https://www.w3schools.com/howto/howto_css_modal_images.asp
  
  Due: Oct. 31
  
  
• Wednesday:
  
  Table_f18.html working with parents and siblings of html elements
  
  DataTable.zip (Karl Saunders)
  
  Histogram_f18.htm (old version Histogram.htm has some jQuery)
  
  Lab: Frequency Analysis
  • Have a textarea where the user can enter some text.
  • When a button is clicked, break the text into an array of letters and count the frequency (number of occurrences) of each letter -- case insensitive. Disable the button. (Before breaking the text into letters, eliminate spaces, punctuation, etc.)
  • Use JavaScript/jQuery to make an svg histogram showing the frequency of each letter.
  • Also calculate the information entropy -- the sum of - p_i log₂(p_i) where p_i is the probability of the i^th letter which we will take to be its frequency divided by the total number of letter occurrences. (The information entropy is the number of bits conveyed by each letter.) You can use Math.log2(x) to obtain the log base 2 of a number. A check on your results is that the information entropy is less than or equal to the information capacity which in this case is log₂ (26) = 4.70044 bits/letter
  • Clear the histogram if the user changes the content of the textarea. Enable the button.
  
  
  Not done yet
  
  Due: Oct. 31