Forward Euler

The Forward Euler method is a method for solving differential equations. It can be thought of as propagating a state along the tangent of a vector field. We can approximate the derivative of a function using function evaluations at multiple timesteps.

The equation for a forward Euler integration of a differential equation $f(x,t)$ is:
$$x_{k+1}=x_{k}+\Delta tf(x_k,t_k)$$
Which can also be written as:
$$\dot{x}=\frac{x_{k+1}-x_k}{h}$$
where $h=\Delta t$, the discrete time between $k$ timesteps. The forward euler method give an estimation of the function at the timestep $kh$. This method produces the most error, but that error can be reduced by using smaller timesteps. The forward euler does not always preserve stability. Euler’s method has a second order numerical error. This error is the difference between the numerical method and the complete taylor series expansion. This $O(h^2)$ error means that to have the error, you will need to take 4 times as many timesteps, or function evaluations.

Python Code

def forward_Euler(f, v):
    return v + dt * f(v)

2D Forward Euler

#basic forward Euler
def forward_euler(deriv_func, x, y, dt):
    delta = deriv_func(x,y)
    return x + delta[0] * dt, y + delta[1] * dt

[[[Backward Euler]] – implicit solver for method.
[[Numerical Errors in Euler’s Method]]
[[Instability of Euler’s Method]]
[[Euler’s Method with Tustin Discretization]]
[[Z-domain of Forward Euler Method]]
[[1D Ball Drop Simulation]] – uses forward Euler method for simulation
Range Bearing Tracking Problem– The “Transition Function” is just Euler’s Method
[[Frequency Warping]] – there is no frequency warping in the forward euler.
[[Forward Euler Difference Equation]]
[[Numerical Integration Difference Equations]]
[[Learjet-25D GCAS]] – used Forward Euler Integration
[[Matlab ode2]] – initial timestep uses forward Euler
Eurofighter Control Law Control Surface and Integration Location – uses forward euler
[[T-Handle Dynamic Simulation Code]] – uses the forward euler method
[[Learjet-25D GCAS Integration]] – uses forward euler