# Py5Vector.dot()

Calculate the dot product between two vectors.

## Examples

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<div class="example-row"><div class="example-cell-image">

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```python
import numpy as np

v1 = py5.Py5Vector(0, 40)
v2 = py5.Py5Vector(10, 10)
angle = v1.angle_between(v2)
print(f'angle = {round(py5.degrees(angle))}°')
# angle = 45°
angle = np.arccos(v1.norm.dot(v2.norm))
print(f'angle = {round(py5.degrees(angle))}°')
# angle = 45°
```

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<div class="example-row"><div class="example-cell-image">

</div><div class="example-cell-code">

```python
def setup():
    global v1
    v1 = py5.Py5Vector(40, 0)


def draw():
    py5.background(255)
    py5.translate(py5.width / 2, py5.height / 2)
    py5.stroke(0)
    py5.stroke_weight(4)
    py5.line(0, 0, v1.x, v1.y)
    vm = py5.Py5Vector(py5.mouse_x - py5.width / 2, py5.mouse_y - py5.height / 2)
    py5.stroke_weight(2)
    py5.stroke(0, 255, 0)
    py5.line(0, 0, vm.x, vm.y)
    v2 = v1.norm.dot(vm) * v1.norm
    py5.stroke(255, 0, 0)
    py5.line(0, 0, v2.x, v2.y)
```

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</div>

## Description

Calculate the dot product between two vectors.

## Signatures

```python
dot(
    other: Union[Py5Vector, np.ndarray],  # vector to calculate the dot product with
) -> Union[float, np.ndarray[np.floating]]
```

Updated on August 23, 2025 19:59:53pm UTC