public void GetExpressionForNthTermTest()
{
int index;
double[] sequence = { 1, 2, 3, 4, 5 };
FiniteCalculus.HasPattern(sequence, out index);
var expression = FiniteCalculus.GetExpressionForNthTerm(FiniteCalculus.GetCoefficientsForNthTerm(sequence, index));
Assert.AreEqual(expression, "1x");
double[] sequence2 = { 1, 4, 8, 13 };
FiniteCalculus.HasPattern(sequence2, out index);
var expression2 = FiniteCalculus.GetExpressionForNthTerm(FiniteCalculus.GetCoefficientsForNthTerm(sequence2, index));
Assert.AreEqual(expression2, "0.8888888889x^2+0.4444444444x+0.1111111111");
}
protected void FindNthTerm_Click(object sender, EventArgs e)
{
if (TextBox1.Text != "")
{
var tokens = TextBox1.Text.Split(',');
double[] seq;
try
{
seq = Array.ConvertAll(tokens, double.Parse);
}
catch
{
Label1.Text = "Could not convert the sequence into an array.";
return;
}
int degree;
if (FiniteCalculus.HasPattern(seq, out degree))
{
var coeff = FiniteCalculus.GetCoefficientsForNthTerm(seq, degree);
var output = FiniteCalculus.GetExpressionForNthTerm(coeff);
Label1.Text = output;
}
else
{
Label1.Text = "Not enough terms to spot a pattern or not a polynomial sequence.";
}
}
else
{
Label1.Text = "No sequence was entered.";
}
}