vector_field#
- k3d.factory.vector_field(vectors, colors=[], origin_color=None, head_color=None, color=255, use_head=True, head_size=1.0, scale=1.0, line_width=0.01, name=None, group=None, custom_data=None, compression_level=0, **kwargs)[source]#
Create a VectorField drawable for displaying dense 2D or 3D grids of vectors of same dimensionality.
By default, the origins of the vectors are assumed to be a grid inscribed in the -0.5 < x, y, z < 0.5 cube or -0.5 < x, y < 0.5 square, regardless of the passed vector field shape, like aspect ratio.
Different grid size, shape and rotation can be obtained using kwargs
vector_field(..., bounds=[-pi, pi, -pi, pi, 0, 1])
vector_field(..., scaling=[scale_x, scale_y, scale_z])
For sparse (i.e. not forming a grid) 3D vectors, use vectors.
- Parameters
vectors (array_like) – Vector field of shape (L, H, W, 3) for 3D fields or (H, W, 2) for 2D fields.
colors (list, optional) –
Array of Hex colors of vectors, by default [].
The array has consecutive pairs (origin_color, head_color) for vectors in row-major order.
origin_color (int, optional) – Hex color of vector origins when colors is empty, by default None.
head_color (int, optional) – Hex color of vector heads when colors is empty, by default None.
color (int, optional) – Hex color of the vectors when colors is empty, by default _default_color.
use_head (bool, optional) – Display vector heads, by default True.
head_size (float, optional) – Vector heads size, by default 1.0.
scale (float, optional) – Scale factor for the vector lengths, by default 1.0.
line_width (float, optional) – Width of vector segments, by default 0.01.
name (str, optional) – Object name, by default None.
group (str, optional) – Name of a group, by default None.
custom_data (dict) – A object with custom data attached to object.
compression_level (int, optional) – Level of data compression [-1, 9], by default 0.
**kwargs – For other keyword-only arguments, see process_transform_arguments.
- Returns
VectorField Drawable.
- Return type
VectorField
See also
Examples#
Basic#
import k3d
import numpy as np
def f(x, y):
return np.sin(y), np.sin(x)
H = W = 10
vectors = np.array([[f(x, y) for x in range(W)] for y in range(H)]).astype(np.float32)
plt_vector_field = k3d.vector_field(vectors,
color=0xed6a5a,
head_size=1.5,
scale=2,
bounds=[-1, 1, -1, 1, -1, 1])
plot = k3d.plot(grid_auto_fit=False)
plot += plt_vector_field
plot.display()
Colormap#
import k3d
import numpy as np
from k3d.colormaps import matplotlib_color_maps
from k3d.helpers import map_colors
from numpy.linalg import norm
p = np.linspace(-1, 1, 10)
def f(x, y, z):
return y * z, x * z, x * y
vectors = np.array([[[f(x, y, z) for x in p] for y in p] for z in p]).astype(np.float32)
norms = np.apply_along_axis(norm, 1, vectors.reshape(-1, 3))
plt_vector_field = k3d.vector_field(vectors,
head_size=1.5,
scale=2,
bounds=[-1, 1, -1, 1, -1, 1])
colors = map_colors(norms, matplotlib_color_maps.Turbo, [0, 1]).astype(np.uint32)
plt_vector_field.colors = np.repeat(colors, 2)
plot = k3d.plot()
plot += plt_vector_field
plot.display()