Recent content by Manuel Goucha

  1. M

    Using Runge–Kutta method for position calc

    Yes, I 've figured that Heun's method was better that RK for this type of code but I wanted to use the more precise and exact method there is, so I thoug as RK was a forth order, that I would be better than Suvat, Heun or verlet
  2. M

    Using Runge–Kutta method for position calc

    Thanks. My problem was to find a method that uses the system of 3 vars, and that doesn't need to have a function to get the acceleration, I needed to give the aceleration instead and it will calculate those 3 vars only by having the force as a given constant, not a function. but it seems to...
  3. M

    Using Runge–Kutta method for position calc

    I think I'm trying to do something impossible here, or I might be cursed with this code, because everything I try to change it always gives me bad results or impossible solving systems. I've changes the NewDerivative to the starting values but it is still giving me wrong values...
  4. M

    Using Runge–Kutta method for position calc

    Yes, I've seen that, but this is an adaptation from another code I had here, is that the only problem? if so, what should I use insted? A 0 Value Derivative? I've tried to use this: NewDerivative.DPos := Vector(0, 0); NewDerivative.DVel := Vector(0, 0); NewDerivative.DAcc :=...
  5. M

    Using Runge–Kutta method for position calc

    The only results I'm getting now is this: Step 0: Position.X = 100; Position.Y = 0; Velocity.X = 0; Velocity.Y = 0; Acceleration.X = 0; Acceleration.Y = 9.8; Step1: Position.X = 1; Position.Y = -0.0081; Velocity.X = 0; Velocity.Y = 0; Acceleration.X = 0; Acceleration.Y =...
  6. M

    Using Runge–Kutta method for position calc

    Thats my problem, I don't know much about 4 order derivative expressions, and I think I'm close but somehow or a numeric error appears or the results get wrong like geting very large numbers or oscilating from positive to negative very quickly, so if I need to have a falling body to get more and...
  7. M

    Using Runge–Kutta method for position calc

    When I run a simulation on a simple particle falling at V0 = 0, I use this conditions: Particle = record P: TVect2; V: TVect2; A: TVect2; F: TVect2; end; procedure SimStart; begin Particle.P := Vector(0, 0); <- Start its Position Particle.A := Vector(0, -9.8); <-...
  8. M

    Using Runge–Kutta method for position calc

    Thanks for all the exaplanations but as you said to use: I've already done that but for some reasson it still doesn't work correctly: P = pos vector V = vel Vector A = Acc vector F = force Vector procedure RK4Integrate(var P, V, A, F: TVect2; DT: Single); type State = record...
  9. M

    Using Runge–Kutta method for position calc

    Hi, I'm trying to calculate a postion and velocity of a body over time using an integrator at each time step, I've only used simple integrators so far but I wanted to a better one that I've seen, RK4 - Runge–Kutta method, to calculate new values of position equation. I've been using the...
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