Homework SourseSo Im having difficulties converting a C program into a new
So I\'m having difficulties converting a C# program into a new one using methods. I\'m getting confused on parameters and how to get multiple return types from the methods.
This is my first code from Assignment 1:
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class Program
{
static void Main(string[] args)
{
char[,] answers = new char[8, 10] //create 2D array of students\' answers
{
{\'A\',\'B\',\'A\',\'C\',\'C\',\'D\',\'E\',\'E\',\'A\',\'D\'},
{\'D\',\'B\',\'A\',\'B\',\'C\',\'A\',\'E\',\'E\',\'A\',\'D\'},
{\'E\',\'D\',\'D\',\'A\',\'C\',\'B\',\'E\',\'E\',\'A\',\'D\'},
{\'C\',\'B\',\'A\',\'E\',\'D\',\'C\',\'E\',\'E\',\'A\',\'D\'},
{\'A\',\'B\',\'D\',\'C\',\'C\',\'D\',\'E\',\'E\',\'A\',\'D\'},
{\'B\',\'B\',\'E\',\'C\',\'C\',\'D\',\'E\',\'E\',\'A\',\'D\'},
{\'B\',\'B\',\'A\',\'C\',\'C\',\'D\',\'E\',\'E\',\'A\',\'D\'},
{\'E\',\'B\',\'E\',\'C\',\'C\',\'D\',\'E\',\'E\',\'A\',\'D\'},
};
string[] students = new string[8] //create array of students\' names
{\"Jack\", \"John\", \"Jill\", \"Mary\", \"Peter\", \"Bob\", \"Nancy\", \"Pat\" };
char[] answerKey = new char[10] //create array of answer key
{\'D\',\'B\',\'D\',\'C\',\'C\',\'D\',\'A\',\'E\',\'A\',\'D\'};
int[] score = new int[10] //create array of scores
{2,2,5,3,3,4,4,4,6,7};
double maxGrade = 0; //initialize maxGrade to use later in calculating final grades for students
for (int i = 0; i < score.Length; i++)
{
maxGrade = maxGrade + score[i];
}
double[] studentscores = new double[8]; //create array to store the scores (but not final %) of students
char[] letterGrade = new char[8]; //create array to store the letter grades
for(int i=0;i<students.Length;i++)
{
for(int j=0;j<score.Length;j++) //get score for each student
{
if (answers[i, j] == answerKey[j])
studentscores[i] = studentscores[i] + score[j];
}
double finalScore = (studentscores[i] / maxGrade) * 100; //calculate final score, then store letter grades into array
if (finalScore <= 100 && finalScore >= 90) letterGrade[i] = \'A\';
else if (finalScore < 90 && finalScore >= 80) letterGrade[i] = \'B\';
else if (finalScore < 80 && finalScore >= 70) letterGrade[i] = \'C\';
else if (finalScore < 70 && finalScore >= 60) letterGrade[i] = \'D\';
else if (finalScore < 60) letterGrade[i] = \'F\';
}
Console.WriteLine(\"Student\\tScore\\tGrade\"); //print Students and their associated scores+grades
for(int i = 0; i < students.Length; i++)
{
Console.WriteLine(students[i] + \"\\t\" + studentscores[i] + \"\\t\" + letterGrade[i]);
}
double[] scores = studentscores;
Array.Sort(scores); //sort scores to be able to calculate median
double median = (scores[scores.Length / 2]); //initialize and calculate median
Console.WriteLine(\"\ Median:\\t\" + median + \"\ \"); //print median value, and create extra line spaces
char[] gradeLetter = new char[5] //create array of each Grade letter for use in histogram
{\'A\',\'B\',\'C\',\'D\',\'F\'};
for (int i = 0; i < gradeLetter.Length; i++)
{
Console.Write(gradeLetter[i] + \":\"); //Create each \"char:\" line
for (int j = 0; j < letterGrade.Length; j++)
{
if(letterGrade[j] == gradeLetter[i]) // for each instance of gradeletter, display a *
{
Console.Write(\"*\");
}
}
Console.WriteLine(); //create new line for each grade
}
}
}
And now for my new code: (ridden with errors at the moment)
class Program
{
static void Main(string[] args)
{
char[,] answers = new char[8, 10] //create 2D array of students\' answers
{
{\'A\',\'B\',\'A\',\'C\',\'C\',\'D\',\'E\',\'E\',\'A\',\'D\'},
{\'D\',\'B\',\'A\',\'B\',\'C\',\'A\',\'E\',\'E\',\'A\',\'D\'},
{\'E\',\'D\',\'D\',\'A\',\'C\',\'B\',\'E\',\'E\',\'A\',\'D\'},
{\'C\',\'B\',\'A\',\'E\',\'D\',\'C\',\'E\',\'E\',\'A\',\'D\'},
{\'A\',\'B\',\'D\',\'C\',\'C\',\'D\',\'E\',\'E\',\'A\',\'D\'},
{\'B\',\'B\',\'E\',\'C\',\'C\',\'D\',\'E\',\'E\',\'A\',\'D\'},
{\'B\',\'B\',\'A\',\'C\',\'C\',\'D\',\'E\',\'E\',\'A\',\'D\'},
{\'E\',\'B\',\'E\',\'C\',\'C\',\'D\',\'E\',\'E\',\'A\',\'D\'},
};
string[] students = new string[8] //create array of students\' names
{\"Jack\", \"John\", \"Jill\", \"Mary\", \"Peter\", \"Bob\", \"Nancy\", \"Pat\" };
char[] answerKey = new char[10] //create array of answer key
{\'D\',\'B\',\'D\',\'C\',\'C\',\'D\',\'A\',\'E\',\'A\',\'D\'};
int[] score = new int[10] //create array of scores
{2,2,5,3,3,4,4,4,6,7};
double[] scores = studentscores; //this was in the Compute
ComputeGrades(answers, answerKey, score);
ComputeStatistics(scores);
DisplayResults(students, studentscores, letterGrade);
Console.ReadKey();
}
public static void ComputeGrades(char[,] answers, char[] answerKey, int[] score)
{
double maxGrade = 0; //initialize maxGrade to use later in calculating final grades for students
for (int i = 0; i < score.Length; i++)
{
maxGrade = maxGrade + score[i];
}
double[] studentscores = new double[8]; //create array to store the scores (but not final %) of students
char[] letterGrade = new char[8]; //create array to store the letter grades
for (int i = 0; i < studentscores.Length; i++)
{
for (int j = 0; j < score.Length; j++) //get score for each student
{
if (answers[i, j] == answerKey[j])
studentscores[i] = studentscores[i] + score[j];
}
double finalScore = (studentscores[i] / maxGrade) * 100; //calculate final score, then store letter grades into array
if (finalScore <= 100 && finalScore >= 90) letterGrade[i] = \'A\';
else if (finalScore < 90 && finalScore >= 80) letterGrade[i] = \'B\';
else if (finalScore < 80 && finalScore >= 70) letterGrade[i] = \'C\';
else if (finalScore < 70 && finalScore >= 60) letterGrade[i] = \'D\';
else if (finalScore < 60) letterGrade[i] = \'F\';
}
}
public static double ComputeStatistics(double[] scores)
{
Array.Sort(scores); //sort scores to be able to calculate median
double median = (scores[scores.Length / 2]);
double avg = scores.Average();
double std = 0;
for (int i = 0; i < scores.Length; i++)
{
//will calculate Std Deviation within
}
//std = Math.Sqrt();
return median;
return avg;
}
public static void DisplayResults(string[] students, double[] studentscores, char[] letterGrade)
{
Console.WriteLine(\"Student\\tScore\\tGrade\"); //print Students and their associated scores+grades
for (int i = 0; i < students.Length; i++)
{
Console.WriteLine(students[i] + \"\\t\" + studentscores[i] + \"\\t\" + letterGrade[i]);
}
Console.WriteLine();
Console.WriteLine(\"{0, -15}{1}\", \"Average:\", avg.ToString());
Console.WriteLine(\"{0, -15}{1}\", \"Std. Dev.:\", std.ToString());
Console.WriteLine(\"{0, -15}{1}\", \"Median:\", median.ToString());
Console.WriteLine();
DrawHistogram(letterGrade);
}
public static void DrawHistogram(char[] letterGrade)
{
char[] gradeLetter = new char[5] //create array of each Grade letter for use in histogram
{\'A\',\'B\',\'C\',\'D\',\'F\'};
for (int i = 0; i < gradeLetter.Length; i++)
{
Console.Write(gradeLetter[i] + \":\"); //Create each \"char:\" line
for (int j = 0; j < letterGrade.Length; j++)
{
if (letterGrade[j] == gradeLetter[i]) // for each instance of gradeletter, display a *
{
Console.Write(\"*\");
}
}
Console.WriteLine(); //create new line for each grade
}
}
}
I need to use local and created values from each method, to use in the other methods. For example, my \"studentscores\" array is created from the ComputeGrades method; however, I am unsure how to correctly return it and be able to pass it into the ComputeStatistics method. Likewise, I\'ll need the average, median, and std devation values from ComputeStatistics() for my DisplayResults(). I have researched and saw stuff about Tuples, but we have not learned anything indepth like that yet. Any help would be appreciated!
Solution
Program.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace A2_XuGuilian
{
class Program
{
//Declare the arrays in the class level seems better. If we put them into every function, it will repeat a few times.
//Plus I don\'t know how to return two result arrays from one function.
public static double[] studentScore = new double[8];
public static char[] grades = new char[8];
public static double score_average, score_std_dev, score_median;
public static void ComputeGrades(ref char[,] answerByStudent, ref char[] answerKey, ref int[] scoreOfEachQuestion)
{
int num_students = 8; // answerByStudent.GetLength(0);
const int num_questions = 10; // answerByStudent.GetLength(1);
for (int idx_stu=0; idx_stu < num_students; idx_stu++)
{
for(int idx_quest=0; idx_quest < num_questions; idx_quest++)
{
if (answerByStudent[idx_stu, idx_quest] == answerKey[idx_quest])
studentScore[idx_stu] += scoreOfEachQuestion[idx_quest];
}
double score_percentage = studentScore[idx_stu] / scoreOfEachQuestion.Sum();
if (score_percentage >= 0.9)
{
grades[idx_stu] = \'A\';
}
else if(score_percentage >= 0.8)
{
grades[idx_stu] = \'B\';
}
else if (score_percentage >= 0.7)
{
grades[idx_stu] = \'C\';
}
else if (score_percentage >= 0.6)
{
grades[idx_stu] = \'D\';
}
else
{
grades[idx_stu] = \'F\';
}
}
}
public static double variance(double[] nums)
{
if (nums.Length > 1)
{
// Get the average of the values
double avg = getAverage(nums);
// Now figure out how far each point is from the mean
// So we subtract from the number the average
// Then raise it to the power of 2
double sumOfSquares = 0.0;
foreach (int num in nums)
{
sumOfSquares += Math.Pow((num - avg), 2.0);
}
// Finally divide it by n - 1 (for standard deviation variance)
// Or use length without subtracting one ( for population standard deviation variance)
return sumOfSquares / (double)(nums.Length - 1);
}
else { return 0.0; }
}
// Square root the variance to get the standard deviation
public static double standardDeviation(double variance)
{
return Math.Sqrt(variance);
}
// Get the average of our values in the array
public static double getAverage(double[] nums)
{
int sum = 0;
if (nums.Length > 1)
{
// Sum up the values
foreach (int num in nums)
{
sum += num;
}
// Divide by the number of values
return sum / (double)nums.Length;
}
else { return (double)nums[0]; }
}
public static void ComputeStatistics()
{
// Get the variance of our values
double varianceValue = variance(studentScore);
// Now calculate the standard deviation
score_std_dev = standardDeviation(varianceValue);
//Get score average
score_average = getAverage(studentScore);
double[] studentScore_tmp = (double[])studentScore.Clone();
Array.Sort(studentScore_tmp);
//compute the median
int size = studentScore_tmp.Length;
int mid = size / 2;
score_median = (size % 2 != 0) ? studentScore_tmp[mid] : (studentScore_tmp[mid] + studentScore_tmp[mid - 1]) / 2;
}
public static void DisplayResults(string[] names)
{
Console.WriteLine(\"{0,-10} {1,-10} {2,-10}\", \"Student\", \"Score\", \"Grade\");
for (int idx_stu = 0; idx_stu < names.Length; idx_stu++)
Console.WriteLine(\"{0,-10} {1,-10} {2,-10}\", names[idx_stu], studentScore[idx_stu], grades[idx_stu]);
Console.WriteLine();
Console.WriteLine();
Console.Write(\"{0,-15}\",\"Average:\");
Console.WriteLine(\"{0:N2}\", score_average);
Console.Write(\"{0,-15}\", \"Std. Dev.:\");
Console.WriteLine(\"{0:N2}\", score_std_dev);
Console.Write(\"{0,-15}\", \"Median:\");
Console.WriteLine(\"{0:N2}\", score_median);
Console.WriteLine();
Console.WriteLine();
DrawHistogram();
}
public static void DrawHistogram()
{
char[] letters = { \'A\', \'B\', \'C\', \'D\', \'F\' };
foreach (char value in letters)
{
Console.Write(value + \" |\");
for (int i = 0; i < grades.Length; i++)
{
if (grades[i] == value)
Console.Write(\"*\");
}
Console.WriteLine();
}
}
public static void Main(string[] args)
{
string[] names = { \"Jack\", \"John\", \"Jill\", \"Mary\", \"Peter\", \"Bob\", \"Nancy\", \"Pat\" };
char[] answerKey = { \'D\', \'B\', \'D\', \'C\', \'C\', \'D\', \'A\', \'E\', \'A\', \'D\' };
int[] scoreOfEachQuestion = { 2, 2, 5, 3, 3, 4, 4, 4, 6, 7 };
char[,] answerByStudent = {
{ \'A\',\'B\',\'A\',\'C\',\'C\',\'D\',\'E\',\'E\',\'A\',\'D\'},
{ \'D\',\'B\',\'A\',\'B\',\'C\',\'A\',\'E\',\'E\',\'A\',\'D\' },
{ \'E\',\'D\',\'D\',\'A\',\'C\',\'B\',\'E\',\'E\',\'A\',\'D\' },
{ \'C\',\'B\',\'A\',\'E\',\'C\',\'C\',\'E\',\'E\',\'A\',\'D\' },
{ \'A\',\'B\',\'D\',\'C\',\'C\',\'D\',\'E\',\'E\',\'A\',\'D\' },
{ \'B\',\'B\',\'E\',\'C\',\'C\',\'D\',\'E\',\'E\',\'A\',\'D\' },
{ \'B\',\'B\',\'A\',\'C\',\'C\',\'D\',\'E\',\'E\',\'A\',\'D\' },
{ \'E\',\'B\',\'E\',\'C\',\'C\',\'D\',\'E\',\'E\',\'A\',\'D\' }
};
ComputeGrades(ref answerByStudent, ref answerKey, ref scoreOfEachQuestion);
ComputeStatistics();
DisplayResults(names);
Console.ReadLine();
}
}
}
