Lab 24

Text File Input/Output

CS211 Lab Policy:

• This lab exercise will not be graded.
• Submit as much as you have completed before the end of the lab period in which it is assigned.
• If you do not finish this lab work, it is to your advantage to finish it outside of class. Please re-submit your finished work to the course web site.
• You may receive help from anyone in completing this lab.
• You may not submit another student's code as part of your lab.

Instructions:

For this lab you will create one MATLAB program named Lab24() in file Lab24.m.  In this assignment you will read statistics about the 2007 NCAA Basketball season (source: http://web1.ncaa.org/stats/StatsSrv/rankings?sportCode=MBB&rpt=wkly  ). Download the file NCAA Basketball Stats.zip and save it in a new empty folder in your MATLAB working directory. After you have downloaded the file, use a "My Documents" window to navigate to the folder that you saved the file in. Then right-click the "NCAA Basketball Stats.zip" file and select "Extract Here". You should see 15 data files appear in this folder. You will read data from these files to accomplish this lab assignment.

Implement MATLAB code that does the following. Save your Lab24.m file in the same directory as your data files.

Task 1: Determine the statistics for which Air Force is nationally ranked.

1. Clear the command window.
    
2. Use the MATLAB dir('*.txt') command to get a list of all the text files in the current folder. If you followed the instructions above and saved the downloaded zip file in an empty folder, this command will return you a list of all the statistics file names in a structure array. Experiment with this command in the command window before you use it in your program.
    
3. For each of the statistic files, do the following:

   Action	MATLAB hints
   Open the file for reading.	File_id = fopen()
   While the file has not been totally read	while ~ feof(File_id)
   Read a single line from the file	Use fgetl()
   Search the line for the string 'Air Force'	Use strfind()
   if 'Air Force' is found
   Extract the first number from the line of text	Use sscanf()
   Display a message that contains the rank and the file name
   Close the file	Use fclose()

   This section of your code should produce output similar to the text shown below (2006 data shown below):

   Air Force is Nationally ranked in Basketball in the following categories:
   Rank  Category
     11  Field-Goal Percentage.txt
     22  Free-Throw Percentage.txt
     10  Personal Fouls Per Game.txt
      1  Scoring Defense.txt
     19  Scoring Margin.txt
     14  Three-Point Field Goals Per Game.txt
      6  Three-Point Field-Goal Percentage.txt
      5  Turnovers Per Game.txt
     11  Won-Lost Percentage.txt

Task 2: Manipulate the 'Scoring Defense' statistics.

4. Create a copy of the file 'Scoring Defense.txt' and call the new file 'Scoring Defense without headers.txt'. Then open this new file, delete the first 5 lines of the file, and save the file. This creates a file that is completely in table format.
    
5. Use the MATLAB textread() command to read the 'Scoring Defense without headers.txt' statistics file into a set of parallel arrays. Use the following  format specifiers in your textread() command.
   • Use %d to read the team rank (1st column)
   • Use %20c to read the team name (2nd column). This will create a 2D array of characters. (You cannot use %s because some of the team names include spaces, and %s reads characters up to the first space.)
   • Use %d to read the number of games played (3rd column).
   • Use %d to read the number of games won (4rd column).
   • Use %*c to read the single slash character between the number of games won and lost (5th column). (But ignore the slash!)
   • Use %d to read the number of games lost (6th column).
   • Use %d to read the total number of points scored by their opponents (7th column).
   • Use %f to read the percentage total number of points scored by their opponents (8th column).
      
6. Produce a line graph of the total number of points scored by each team's opponents. The graph should look like (2006 data shown below):
   
   
    

Task 3: Manipulate the original 'Scoring Defense' statistics.

7. Now use textscan() to read the original 'Scoring Defense.txt' data file. To do this, you must read the first 5 lines of the file before using textscan(). Perform the following steps:
   1. Open the file using fopen().
   2. Read the first 5 lines using fgetl().
   3. Read the entire table of data into a single cell array using textscan().
   4. Close the file using fclose().
       
8. Produce a scatter plot that compares the number of games won verses the number of games lost. The graph should look like (2006 data shown below):
   
   
   
    

Please make sure you understand the differences and similarities between the textscan() and the textread() commands.

Turn-in:

Submit your Lab24.m file.