Unified X (time) / Y (price) unit?

[FREEN]

I admit I didn´t do to much forum reseach on this question, sorry:

In order to do calculations such as trigonometry and vectors a single unit for the X and Y axis would simplify things. It there a mathematicaly safe way to do such a conversion (and back to time/price)?

I noticed the following methods in the ChartControl namespace that I guess might be of value:

GetXByBarIdx()
GetXByTime()
GetYByValue()

Kindly, Fredrik

[FREEN]

Feel free to delete this thread... I realize the units in most (all) cases wont matter.

My problem is out of the scoop of programming. If anyone happens to know, I´m happy to know:

1. how k values (y= kx + a) can be converted to degrees/radians
2. if the the sum om k values in a triangle is a constant (if so wich constant).

[NinjaTrader_AlexG]

Hello FREEN,
Thanks for posting.

1. To convert radians to degrees you would need to multiply the radian value by pi/180. The inverse (degrees to radians) would be multiply your radian value by 180/pi.

2. The k in the formula you are using (y= kx + a) is the constant of proportionality or slope. This constant is not a specific part of a triangle but rather a constant that can be used to determine another value of another triangle based on one triangles value.

I am little confused on the formula you are using though as most directly proportional relantionships would simple be y= kx. Now y=mx+b would be a slope formula which is close to the formula you have shown. Since you mentioned triangles I assumed that you are using the k for similar triangle.

If this is not the case can you tell how the formula you mentioned is being used and I can further assist or please let us know if we may be of further assistance for anything NinjaTrader.

[FREEN]

Alex, thanks for replying on a non NT related question!

I had to refresh some highschool trigonometry before I ended up with the following methods:


/// <summary>
/// k value (slope) in y = kx + m
/// </summary>
/// <param name="x1">point 1 x</param>
/// <param name="y1">point 1 y</param>
/// <param name="x2">point 2 x</param>
/// <param name="y2">point 2 y</param>
/// <returns></returns>
private double GetVectorK(double x1, double y1, double x2, double y2)
{
return (y2-y1) / (x2-x1);
}

/// <summary>
/// m value (y intercept) in y = kx + m
/// </summary>
/// <param name="x">x value (non zero!)</param>
/// <param name="y">y value</param>
/// <param name="k">k value (slope)</param>
/// <returns>m</returns>
private double GetVectorM(double x, double y, double k)
{
return ((k * x) - y) * -1;
}

/// <summary>
/// Vector angle to x-axis. (Pos 0-90 deg in Q1. Neg 0-90 deg in Q4. Not valid for Q2 and Q3).
/// </summary>
/// <param name="k">k value of vector (y = kx + m)</param>
/// <returns>Angle in deg</returns>
private double GetVectorXaxisAngle(double k)
{
if (k == double.NaN) return 90;

return Math.Atan(k) * (180/Math.PI);
}