Assignment Number 8 Lab Assignment Due Date: Wednesday, October 31, 2018 CS 1057 C Programming - Fall 2018

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1 Assignment Number 8 Lab Assignment Due Date: Wednesday, October 31, 2018 CS 1057 C Programming - Fall 2018 Purpose: create a batch program use a version control system to obtain data (git) read and process input data from a file create short, cohesive functions use stepwise refinement in writing your program use a driver to insure your program works Prerequisites: Review through Chapter 7 in the textbook before attempting this lab. Background: OMR, or Optical Mark Readers, are an old-fashioned piece of hardware for collecting information on a form where people mark stylized bubbles to indicate their answers to questions rather than having to write them out. Using a quality printed form and precise shading by the person taking the test, OMR technology can consistently provide 99.9% accuracy on read data. OMR cannot recognize hand-printed or machine-printed characters. They are simple devices that shine light through the paper and look for the dark black marks that indicate a selection. Optical answer sheets, more commonly known as "bubble sheets," are used to conduct academic tests by having test takers fill in the oval bubbles that correspond to answers for the test questions. In the past, bubble sheets had to be read by OMR scanners. Today, though, you can use a scanner, a computer and software to scan bubble sheets as well as analyze and grade them. Page 1 of 6

2 When an OMR reads a bubble sheet, it generates a file of data indicating which bubbles are selected. A sample piece of this data file looks like the following: 00000addabbcadad 45350acdccbdabad 58394addcbcdaacd 34517cddabbcadcd with each line representing an identification number and the answers they selected for the questions on the bubble sheet. The first line of the file identified by needs to be treated as special, since it represents the correct answers for each question. When the OMR reads the bubble sheets, the data file generated is sent to GitHub for processing by C programmers, just like you! Git is a free and open source distributed version control system designed to handle everything from small to very large projects with speed and efficiency. GitHub Inc. is a web-based hosting service for version control using Git. It is mostly used for computer code. It offers all of the distributed version control and source code management (SCM) functionality of Git as well as adding its own features. It provides access control and several collaboration features such as bug tracking, feature requests, task management, and wikis for every project. Page 2 of 6

3 Problem Specification: Armed with the file description information, write a program to read in the data file and process it as follows. Your program should begin with the following display GRADING OMR FORMS PROGRAM WRITTEN IN C Program written by Douglas Digital. Program compiled on Oct 22, 2018 at 16:42:41. Read in the answer key: Question 1: a Question 2: d Question 3: d Question 4: a Question 5: b Question 6: b Question 7: c Question 8: a Question 9: d Question 10: a Question 11: d Read in the rest of the file, and display the following information for each test taker: ANSWER SELECTION SUMMARY Ident Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9 Q10 Q a cx d cx cx b dx a bx a d a cx d cx b b dx a ax cx d cx d d a b b ax a d cx d The X next to the selection indicates the answer selected is incorrect. Generate a table below the list above summarizing which questions were missed most frequently by the test takers. COUNT AND PERCENT OF ANSWERS MARKED INCORRECT Ident Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9 Q10 Q % 66% 0% 66% 33% 0% 100% 0% 66% 66% 0% Finally, generate another table displaying the grade for the test by ID. GRADING SUMMARY Identification Grade % % % Page 3 of 6

4 Tasks: 1. Get the data file 'newomr.txt' using the Linux 'git' command as follows: git clone 2. Write a function read in the data file. Use this prototype for the function. void processomrdata( char *filename ); This function should open the file for reading, read in the first line and process that as the "key", and then loop over the rest of the file until all the data is read. Note: the Linux command wc l will return the number of lines in a file. You can use this to verify your program is seeing all the input lines. You can also use the Linux command tail to see the last 10 lines of a file. You can then make sure your program is seeing all of the data. Test this function first before writing the rest of the program. Testing your program in steps makes it much easier to debug than trying to write a large program all at once. Write a driver for the function to insure it is working before proceeding with the rest of the assignment. 3. Write the rest of the program to generate the output asked for above. 4. Some of the data didn't scan properly and it's reported as errors in the data file. Account for those errors in your code, and have the information displayed by your batch program so someone can go into the data file and fix them. (We re not going to fix them for now, just report on them!) 5. This time, we had 11 questions on the bubble sheet. Next time there may be more or less. Write your program with an eye towards the number of questions sometimes being different. Page 4 of 6

5 Sample Driver: #include <stdio.h> #include <stdlib.h> // Simple driver to test out reading in data from the latest omr file // and printing out the data read in by columns. #define LIMIT_TO_READING_LINES 3 #define NUMBER_OF_QUESTIONS_PER_STUDENT 11 #define ERROR_CODE_IN_INPUT_SCANNING 'e' void processomrdata( char *fname ); void printsingleentry( int id, char scores[] ); int main() { processomrdata( "newomr.txt" ); // probably want to prompt for this name. return EXIT_SUCCESS; void processomrdata( char *fname ) { FILE *IN = fopen( fname, "r" ); int id; char scores[ NUMBER_OF_QUESTIONS_PER_STUDENT ]; int count = 0; int i; if (! IN ) { printf( "Error opening input file %s.\n", fname ); perror( fname ); return; while ( fscanf( IN, "%d", &id ) == 1 ) { count++; printf( "Response %d, ID = %d.\n", count, id ); for ( i = 0; i < NUMBER_OF_QUESTIONS_PER_STUDENT; i++ ) { fscanf( IN, "%c", &scores[ i ] ); printf( "(%d) %d. >%c<\n", count, i, scores[ i ] ); printsingleentry( id, scores ); if ( count >= LIMIT_TO_READING_LINES ) break; void printsingleentry( int id, char scores[] ) { int i; printf( "ID='%5.5d' ", id ); for ( i = 0; i < NUMBER_OF_QUESTIONS_PER_STUDENT; i++ ) printf( "'%c' ", scores[ i ] ); puts(""); puts(" " ); Page 5 of 6

6 Note that the driver will be downloaded by git when you issue that command, so you do not need to type it in or copy and paste it. You can use it to test reading the data. Page 6 of 6