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image_ module

Utilities for images.

hstack_image_arrays function

hstack_image_arrays(
    a,
    b
)

Stack NumPy images horizontally.

save_animation function

save_animation(
    fname,
    index,
    plot_func,
    *args,
    delta=None,
    step=1,
    fps=3,
    writer_kwargs=None,
    show_progress=True,
    pbar_kwargs=None,
    to_image_kwargs=None,
    **kwargs
)

Save animation to a file.

Args

fname : str
File name.
index : sequence
Index to iterate over.
plot_func : callable

Plotting function.

Must take subset of index, *args, and **kwargs, and return either a Plotly figure, image that can be read by imageio.imread, or a NumPy array.

*args
Positional arguments passed to plot_func.
delta : int
Window size of each iteration.
step : int
Step of each iteration.
fps : int

Frames per second.

Will be translated to duration by 1000 / fps.

writer_kwargs : dict
Keyword arguments passed to imageio.get_writer.
show_progress : bool
Whether to show the progress bar.
pbar_kwargs : dict
Keyword arguments passed to ProgressBar.
to_image_kwargs : dict
Keyword arguments passed to plotly.graph_objects.Figure.to_image.
**kwargs
Keyword arguments passed to plot_func.

Usage

>>> from vectorbtpro import *

>>> def plot_data_window(index, data):
...     return data.loc[index].plot()

>>> data = vbt.YFData.pull("BTC-USD", start="2020", end="2021")
>>> vbt.save_animation(
...     "plot_data_window.gif",
...     data.index,
...     plot_data_window,
...     data,
...     delta=90,
...     step=10
... )

vstack_image_arrays function

vstack_image_arrays(
    a,
    b
)

Stack NumPy images vertically.