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COMP2500 – Programming in the Large – Assignment One

Criteria and Results
Average class result		10
Adherence to code format rules (0-3)
no violation of code format rules	3	3 ✔
small number of minor violations	2
significant number of violations	1
work with little or no academic merit	0
Quality of code (0-6)
code that is correct, clear and succint	6	6 ✔
code with small number of minor problems	4
code that is clearly incorrect, too complex or hard to understand	2
work with little or no academic merit	0
Our testing of AssessmentOptions.java (0-6)
no errors detected	6	6 ✔
one or two minor problems detected	4
substantial number of problems detected	2
work with little or no academic merit	0
Total Possible Marks	15	15/15

Submitted Code

View the JavaDoc

/* * Author: Ned Martin #40529927 * * Creation Date: 21-AUG-2003 * * Copyright: Ned Martin * * Description: Assignment 1 for COMP2500 * * Tab Stops: Eight spaces */ import java.io.*; // Provides standard IO import java.util.*; // Provides StringTokenizer import java.text.*; // Provides DecimalFormat /** * Accepts a student name and three results and formats and prints them. * * Input is assumed to be valid. Invalid input is not handled. Maximum of 50 * student records, minimum of 2 student records allowed * * @author Ned Martin * @version Final 21-AUG-2003 */ public class AssessmentOptions { /** * Prints information about student results. * * Accepts input, formats appropriately and prints output * * @return None * @param -i String input file * @param -o String output file */ public static void main ( String[] args ) { // initialising variables String line, // holds input lines inputFile = "", outputFile = "default.out"; boolean input = false, output = false; // calculation variables double sumA = 0.0, sumB = 0.0, stdDevA = 0.0, stdDevB = 0.0, meanA = 0.0, meanB = 0.0; int numStudents = 0; // holds individual student results double[][] marks = new double [50][2]; // holds running totals, avoids useage of public vars double[] totals = new double [3]; // holds student names String[] students = new String [50]; // parse args if args exist if (args.length >= 2) { // if input arg set input file if (args[0].equals("-i")) { inputFile = args[1]; input = true; } // if output arg set output file else if (args[0].equals("-o")) { outputFile = args[1]; output = true; } } if (args.length == 4) { // if input arg set input file if (args[2].equals("-i")) { inputFile = args[3]; input = true; } // if output arg set output file else if (args[2].equals("-o")) { outputFile = args[3]; output = true; } } try { // read input from file if (input) { BufferedReader in = new BufferedReader(new FileReader(inputFile)); // capture line while ((line = in.readLine()) != null) { // send line to parser parse(line, totals, marks, students); } in.close(); } // read from standard in else { BufferedReader in = new BufferedReader(new InputStreamReader(System.in)); // capture line while ((line = in.readLine()) != null) { // send line to parser parse(line, totals, marks, students); } } numStudents = (int) totals[0]; // print student results array for (int i = 0; i < numStudents ; i++ ) { print(students[i]+" " +format(marks[i][0])+" " +format(marks[i][1]), outputFile, output, i); } // calculate means meanA = totals[1]/totals[0]; meanB = totals[2]/totals[0]; // calculate standard deviations stdDevA = stdDev(marks, meanA, numStudents, 0); stdDevB = stdDev(marks, meanB, numStudents, 1); // print means print("mean "+format(meanA)+" "+format(meanB), outputFile, output, 1); // print standard deviations print("std dev "+format(stdDevA)+" " +format(stdDevB), outputFile, output, 1); } // catch exceptions catch (IOException e) { System.err.println("IO Exception: Check input\n"+e); System.exit(1); } catch (ArrayIndexOutOfBoundsException e) { System.err.println("Array out of bounds exception:" +" Check input\n"+e); System.exit(1); } catch (NoSuchElementException e) { System.err.println("No such element exception:" +" Check input\n"+e); System.exit(1); } catch (NumberFormatException e) { System.err.println("Number format exception:" +" Check input\n"+e); System.exit(1); } } /** * Calculates standard deviation * * Accepts numerical input and calculates standard deviation * * @return Double representing standard deviation of input values */ private static double stdDev ( double[][] marks, // array of student's results double mean, // average of results int numStudents, // number of students int x // mean type selector ) { double stdDev = 0.0; // calculate standard deviation for (int i = 0; i < numStudents ; i++ ) { stdDev = stdDev + ( (marks[i][x] - mean) * (marks[i][x] - mean)); } // return standard deviation return Math.sqrt(stdDev / (double) (numStudents - 1) ); } /** * Format a number. * * Accepts a double and returns a formatted string * * @return String representing formatted double */ private static String format ( double number // number to format ) { // format number DecimalFormat df = new DecimalFormat("0.00"); // return number return df.format(number); } /** * Parse input. * * Accepts input and parses input into various arrays * * @return None, however various arrays are altered by this * function */ private static void parse ( String line, // input line to parse double[] totals, // increment running totals double[][] marks, // store student results String[] students // store student names ) { double numStudents = totals[0] + 1; StringTokenizer st = new StringTokenizer(line); // assume exact string format "name int int int" students[(int) numStudents-1] = st.nextToken(); // parse input line and calulate values int a = Integer.parseInt(st.nextToken()); int b = Integer.parseInt(st.nextToken()); int c = Integer.parseInt(st.nextToken()); double d = a+b+c- Math.min(Math.min(a,b),Math.min(b,c)); double e = (double) ((a+b+c)/3.0)*2; totals[0] = numStudents; totals[1] = totals[1] + d; // setting sumA totals[2] = totals[2] + e; // setting sumB marks[(int) numStudents-1][0] = d; // method 1 marks[(int) numStudents-1][1] = e; // method 2 } /** * Prints data. * * Accepts input from main function and prints it accordingly * * @return None */ private static void print ( String line, // line to print String outputFile, // file to print to boolean output, // if true, prints to file int overwrite // specifies whether to overwrite ) { boolean append = true; try { // print to file if (output) { // overwrite only on first print if (overwrite == 0) { append = false; } BufferedWriter out = new BufferedWriter(new FileWriter(outputFile, append)); out.write(line+"\n"); out.close(); } // print to standard out else { System.out.println(line); } } // catch exceptions catch (IOException e) { System.err.println("IO Exception:" +" Check output file\n"+e); System.exit(1); } } }
Code © Copyright 2003 Ned Martin

09-Sep-2003