public void TestEmptyTableWeight()
{
var calc = new AverageCalc();
var emptyTable = new SubjectDetailsViewModel[1];
var result = calc.WeightedAverage(emptyTable);
}
public void TestWeightedMean()
{
List<SubjectDetailsViewModel> grades = new List<SubjectDetailsViewModel>();
var rnd = new Random();
var sum = 0.0;
var num = 0.0;
for (var i = 0; i < 5; i++)
{
var val = rnd.Next(2, 6);
var weight = rnd.Next(1, 10);
var grade = new SubjectDetailsViewModel()
{
grade_value = val,
grade_weight = weight
};
grades.Add(grade);
sum += grade.grade_weight * grade.grade_value;
num += grade.grade_weight;
}
var mean =Math.Round(sum/num, 2);
var calc = new AverageCalc();
var result = calc.WeightedAverage(grades.ToArray());
Assert.AreEqual(mean, result);
}
/// <summary>
/// Calculates average from given grades.
/// </summary>
/// <param name="grades">Array of grades as SubjectDetailsViewModel.</param>
/// <returns></returns>
public double Average(SubjectDetailsViewModel[] grades)
{
double sum = 0;
if (grades != null)
{
if (grades.Length != 0)
{
foreach (var grade in grades)
{
if(grade == null)
throw new Exception("There is no grade! (null)");
sum = sum + grade.grade_value;
}
return Math.Round((sum/grades.Length),2);
}
}
return 0;
}
/// <summary>
/// Calculates a weighted average from given grades.
/// </summary>
/// <param name="grades">Array of grades as SubjectDetailsViewModel.</param>
/// <returns></returns>
public double WeightedAverage(SubjectDetailsViewModel[] grades)
{
if (grades != null)
{
if (grades.Length != 0)
{
double sumTop = 0;
double sumBot = 0;
foreach (var grade in grades)
{
if (grade == null)
throw new Exception("There is no grade! (null)");
sumTop = sumTop + (grade.grade_value*grade.grade_weight);
sumBot = sumBot + (grade.grade_weight);
}
return Math.Round((sumTop/sumBot), 2);
}
}
return 0;
}
public async Task<IHttpActionResult> PutSubjectDetails(int id, SubjectDetailsViewModel subjectDetails)
{
SubjectDetails local= await db.SubjectDetails.FindAsync(id);
local.grade_date = subjectDetails.grade_date;
local.grade_desc = subjectDetails.grade_desc;
local.grade_value = subjectDetails.grade_value;
local.grade_weight = subjectDetails.grade_weight;
local.user_id = subjectDetails.user_id;
if (!ModelState.IsValid)
{
return BadRequest(ModelState);
}
if (id != subjectDetails.id)
{
return BadRequest();
}
db.Entry(local).State = EntityState.Modified;
try
{
await db.SaveChangesAsync();
}
catch (DbUpdateConcurrencyException)
{
if (!SubjectDetailsExists(id))
{
return NotFound();
}
else
{
throw;
}
}
return StatusCode(HttpStatusCode.NoContent);
}
public async Task<IHttpActionResult> PostSubjectDetails(SubjectDetailsViewModel subjectDetails)
{
if (!ModelState.IsValid)
{
return BadRequest(ModelState);
}
SubjectDetails newSubjectDetail = new SubjectDetails()
{
grade_date = subjectDetails.grade_date,
grade_desc = subjectDetails.grade_desc,
grade_value = subjectDetails.grade_value,
grade_weight = subjectDetails.grade_weight,
sub_id = subjectDetails.sub_id,
user_id = subjectDetails.user_id
};
db.SubjectDetails.Add(newSubjectDetail);
await db.SaveChangesAsync();
return CreatedAtRoute("DefaultApi", new { id = subjectDetails.id }, subjectDetails);
}
/// <summary>
/// Calls edit form for grade
/// </summary>
/// <param name="sub">Subject to which grade will be added</param>
private void AddGradeToSubject(SubjectsViewModel sub)
{
SubjectDetailsViewModel grade = new SubjectDetailsViewModel()
{
sub_id = sub.id,
grade_weight = 1
};
var editForm = new EditGradeForm(grade, true);
editForm.ShowDialog();
UpdateMainForm();
}