public double GetDotProduct(LinearEquation p)
{
p = p ?? new LinearEquation(0, 0);
var q = this;
var qdotp = q * p;
return(qdotp[0] + qdotp[1]);
}
internal LinearEquation GetReciprocal(LinearEquation r)
{
r = r ?? new LinearEquation(0, 0);
var recipSlope = -1 * (1 / Slope);
var recipIntercept = r.Intercept - recipSlope * r.Slope;
return(new LinearEquation(recipSlope, recipIntercept));
}
public double GetAngle(LinearEquation p)
{
p = p ?? new LinearEquation(0, 0);
var q = this;
var cosTheta = q.GetCosTheta(p);
var acosRadians = System.Math.Acos(cosTheta);
return(System.Math.Round(acosRadians * (180 / System.Math.PI), RoundTo));
}
internal static Tuple <double, double, double> GetImplicitCoeffs(LinearEquation p, LinearEquation q)
{
var v = q - p;
var ab = new LinearEquation(v[0], -1 * v[1]).GetTranspose();
var a = ab[0];
var b = ab[1];
var c = -1 * a * p[0] - b * p[1];
return(new Tuple <double, double, double>(a, b, c));
}
internal static LinearEquation GetLineFromVectors(LinearEquation p, LinearEquation q)
{
var abc = GetImplicitCoeffs(p, q);
var a = abc.Item1;
var b = abc.Item2;
var c = abc.Item3;
var slope = (-1 * a) / b;
var intercept = (-1 * c) / b;
return(new LinearEquation(slope, intercept));
}
public LinearEquation GetIntersect(LinearEquation p)
{
p = p ?? new LinearEquation(0, 0);
var interceptTick = p.Intercept;
var slopeTick = p.Slope;
var interceptX = (interceptTick - Intercept) / (Slope - slopeTick);
//plug it back into either
var inteceptY = SolveForY(interceptX);
return(new LinearEquation(interceptX, inteceptY));
}
/// <summary>
/// Parse a string in the format of [intercept],[slope]
/// where both intercept and slope may be parsed to doubles
/// and are joined by a comma.
/// </summary>
/// <param name="csv"></param>
/// <param name="lq"></param>
/// <returns></returns>
public static bool TryParse(string csv, out LinearEquation lq)
{
lq = null;
if (string.IsNullOrWhiteSpace(csv) || !csv.Contains(","))
{
return(false);
}
var interceptStr = csv.Split(',')[0];
var slopeStr = csv.Split(',')[1];
if (double.TryParse(interceptStr, out var intercept) && double.TryParse(slopeStr, out var slope))
{
lq = new LinearEquation(slope, intercept);
}
return(lq != null);
}
public double GetDistance(LinearEquation p)
{
p = p ?? new LinearEquation(0, 0);
return((this - p).EuclideanNorm);
}