.create_quiver()

The .create_quiver() function in Plotly’s figure_factory module generates a quiver plot, which is used to visualize vector fields. It is commonly applied in physics, fluid dynamics, and engineering to depict direction and magnitude of vectors in a given space.

Syntax

import plotly.figure_factory as ff

quiver = ff.create_quiver(
    x, y, u, v,
    scale=0.1,
    arrow_scale=0.3,
    angle=math.pi/9,
    line=dict(color='blue', width=1)
)

Parameters:

• x: A list or NumPy array representing the x-coordinates of the arrow bases.
• y: A list or NumPy array representing the y-coordinates of the arrow bases.
• u: A list or NumPy array representing the x-components (horizontal) of the arrow vectors.
• v: A list or NumPy array representing the y-components (vertical) of the arrow vectors.
• scale (default=0.1): A scaling factor for the arrow lengths.
• arrow_scale (default=0.3): Determines the size of the arrowhead.
• angle (default=math.pi/9): The opening angle of the arrowhead.
• line (optional): A dictionary defining the line properties, such as color and width.

Examples

Basic Quiver Plot

In this example, a quiver plot is created to visualize a circular vector field where arrows radiate outward in a radial pattern:

import plotly.figure_factory as ff
import numpy as np
import plotly.graph_objects as go

# Generate circular grid points
theta = np.linspace(0, 2 * np.pi, 20)
x = np.cos(theta) * 3
y = np.sin(theta) * 3

# Define vector components with radial pattern
u = -np.sin(theta)
v = np.cos(theta)

# Create quiver plot
fig = ff.create_quiver(x, y, u, v, scale=0.2, arrow_scale=0.5)
fig.update_layout(title="Circular Quiver Plot")
fig.show()

The output will be:

Customized Quiver Plot

This example demonstrates how to customize arrow styles in a quiver plot by modifying colors, line width, and scaling:

import plotly.figure_factory as ff
import numpy as np
import plotly.graph_objects as go

# Generate structured grid
x, y = np.meshgrid(np.linspace(-5, 5, 10), np.linspace(-5, 5, 10))
u = -y / np.sqrt(x**2 + y**2)
v = x / np.sqrt(x**2 + y**2)

# Flatten arrays for plotting
x, y, u, v = x.flatten(), y.flatten(), u.flatten(), v.flatten()

# Create quiver plot with optimized arrow size
fig = ff.create_quiver(x, y, u, v, scale=1, arrow_scale=0.5, line=dict(color='red', width=2))
fig.update_layout(title="Grid-Based Quiver Plot")
fig.show()