import numpy as np
from stimupy.utils import resolution
__all__ = [
"grid",
]
[docs]def grid(
visual_size=None,
ppd=None,
shape=None,
element_size=None,
intensity_background=0.0,
intensity_grid=1.0,
):
"""Hermann's (1870) grid
Parameters
----------
visual_size : Sequence[Number, Number], Number, or None (default)
visual size [height, width] of grating, in degrees
ppd : Sequence[Number, Number], Number, or None (default)
pixels per degree [vertical, horizontal]
shape : Sequence[Number, Number], Number, or None (default)
shape [height, width] of grating, in pixels
element_size : (float, float, float)
height, width and thickness of individual elements in degree visual angle
intensity_background : float
value of background
intensity_grid : float
value of grid
Returns
-------
dict[str, Any]
dict with the stimulus (key: "img"),
empty mask (key: "target_mask"),
and additional keys containing stimulus parameters
References
----------
Hermann L (1870).
Eine Erscheinung simultanen Contrastes".
Pflügers Archiv für die gesamte Physiologie. 3: 13-15.
https://doi.org/10.1007/BF01855743
"""
if element_size is None:
raise ValueError("grid() missing argument 'element_size' which is not 'None'")
# Resolve resolution
shape, visual_size, ppd = resolution.resolve(shape=shape, visual_size=visual_size, ppd=ppd)
if len(np.unique(ppd)) > 1:
raise ValueError("ppd should be equal in x and y direction")
eheight, ewidth, ethick = resolution.lengths_from_visual_angles_ppd(
element_size, np.unique(ppd)
)
if eheight <= ethick:
raise ValueError("Element thickness larger than height")
if ewidth <= ethick:
raise ValueError("Element thickness larger than width")
if ethick <= 0:
raise ValueError("Increase element thickness")
img = np.ones(shape) * intensity_background
for i in range(ethick):
img[i::eheight, :] = intensity_grid
img[:, i::ewidth] = intensity_grid
stim = {
"img": img,
"target_mask": np.zeros(shape).astype(int), # TODO: add mask
"visual_size": visual_size,
"ppd": ppd,
"shape": shape,
"element_size": element_size,
"intensity_background": intensity_background,
"intensity_grid": intensity_grid,
}
return stim
def overview(**kwargs):
"""Generate example stimuli from this module
Returns
-------
stims : dict
dict with all stimuli containing individual stimulus dicts.
"""
default_params = {
"visual_size": 10,
"ppd": 30,
}
default_params.update(kwargs)
# fmt: off
stimuli = {
"hermann_grid": grid(**default_params, element_size=(1.5, 1.5, 0.2))
}
# fmt: on
return stimuli
if __name__ == "__main__":
from stimupy.utils import plot_stimuli
stims = overview()
plot_stimuli(stims, mask=False, save=None)
