Kernels¶
Create kernels¶
New kernels can be defined by creating a closure object where the inner function takes the spatial and/or temporal frequencies as argument, depending on whether it is a spatial, temporal, or spatiotemporal kernel.
An example is shown below:
def create_my_kernel(): def evaluate(w, kx, ky): # implementation return evaluate
Available kernels¶
Spatial¶
- Gaussian
- Difference of Gaussian
- Dirac delta
-
pylgn.kernels.spatial.
create_delta_ft
(shift_x=array(0.) * deg, shift_y=array(0.) * deg)[source]¶ Create delta_ft closure
Parameters: - shift_x (float/quantity scalar) – Shift in x-direction
- shift_y (float/quantity scalar) – Shift in y-direction
Returns: out – Evaluate function
Return type: function
-
pylgn.kernels.spatial.
create_dog_ft
(A=1, a=array(0.62) * deg, B=0.85, b=array(1.26) * deg, dx=array(0.) * deg, dy=array(0.) * deg)[source]¶ Create Fourier transformed difference of Gaussian function closure
Parameters: - A (float) – Center peak value
- a (float/quantity scalar) – Center width
- B (float) – Surround peak value
- b (float/quantity scalar) – Surround width
- dx (float/quantity scalar) – shift in x-direction
- dy (float/quantity scalar) – shift in y-direction
Returns: out – Evaluate function
Return type: function
-
pylgn.kernels.spatial.
create_gauss_ft
(A=1, a=array(0.62) * deg, dx=array(0.) * deg, dy=array(0.) * deg)[source]¶ Create Fourier transformed Gaussian function closure.
Parameters: - A (float) – peak value
- a (float/quantity scalar) – Width
- dx (float/quantity scalar) – shift in x-direction
- dy (float/quantity scalar) – shift in y-direction
Returns: out – Evaluate function
Return type: function
Temporal¶
- Dirac delta
- Biphasic
- Difference of exponentials
-
pylgn.kernels.temporal.
create_biphasic_ft
(phase=array(43.) * ms, damping=0.38, delay=array(0.) * ms)[source]¶ Create Fourier transformed Biphasic closure
Parameters: - phase (float/quantity scalar) – Delay
- damping (float) – Damping factor
- delay (float/quantity scalar) – Delay
Returns: out – Evaluate function
Return type: function