Based on the experimental results, I can provide a description, domain, and code approximation for the function implemented by f(x).

[DESCRIPTION]:
The function seems to be a non-linear function that takes a numerical input and returns a corresponding output. It appears to have a decreasing trend overall, with some oscillations and irregularities throughout the domain.

[DOMAIN]:
The domain of the function is the set of all numerical inputs. However, there is an interval within the domain where the function displays unexpected behavior. From the experimental results, it seems that the function behaves differently for values between approximately -4 and 4. Within this interval, the function exhibits rapid changes and oscillations.

[CODE]:
Here's a python code approximation of the function based on the experimental results:

```python
def f(x):
    if x >= -4 and x <= 4:
        return x * (x - 3) * (x + 1)
    else:
        return -0.1 * x ** 3 + 3 * x - 0.7
```

Please note that this code is just an approximation based on the experimental data, and it may not perfectly represent the actual implementation of the function.