Can someone explain how to create the vector field?

[Jack071120]

Hi there. I've tried to use the VectorField commend with defined function. However, I'm stuck on the coordinate system parameter. I can't find any vector field example using manimgl, so it would be great if someone could give me an example and explain it briefly. Thx!

[TonyCrane]

Just like this? :

class Code1537(Scene):
    def construct(self):
        plane = NumberPlane()
        vector_field = VectorField(
            lambda x, y: np.array([x, y]), plane,
            magnitude_range=(0, 5),
            vector_config={"thickness": 0.025}
        )
        self.add(plane, vector_field)

And you can also learn it from 3b1b's newest video code: https://github.com/3b1b/videos/blob/master/_2021/matrix_exp.py
Such as:

class Code1537(Scene):
    def construct(self):
        matrix = np.array(self.matrix)
        def func(x, y):
            return 0.15 * np.dot(matrix.T, [x, y])

        plane = NumberPlane()
        vector_field = VectorField(
            func, plane,
            magnitude_range=(0, 2),
            vector_config={"thickness": 0.025}
        )
        self.add(plane, vector_field)

[Jack071120]

yea that's exactly what I want. Thx !

[Acpear]

The anwser is perfect! I am looking for this kind for a LONG time. Thanks!