src.acoustools.Stiffness

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 1import torch
 2from acoustools.Force import compute_force
 3from acoustools.Utilities import create_points, TRANSDUCERS
 4
 5from torch import Tensor
 6
 7def stiffness_finite_differences(activation:Tensor, points:Tensor, board:Tensor|None=None, delta= 0.001):
 8    '''
 9    Computes the stiffness at a point as the gradient of the force. Force computed analytically and then finite differences used to find the gradient \n
10    Computed as `-1* (Fx + Fy + Fz)` where `Fa` is the gradient of force in that direction \n 
11    :param activation: Hologram
12    :param points: Points of interest
13    :param board: Transducers to use
14    :param delta: finite differences step size
15    
16    '''
17
18    if board is None:
19        board = TRANSDUCERS
20
21    dx = create_points(1,1,delta,0,0)
22    dy = create_points(1,1,0,delta,0)
23    dz = create_points(1,1,0,0,delta)
24
25
26
27    Fx1 = compute_force(activation,points + dx,board=board)[0]
28    Fx2 = compute_force(activation,points - dx,board=board)[0]
29
30    Fx = ((Fx1 - Fx2) / (2*delta))
31
32    Fy1 = compute_force(activation,points + dy,board=board)[1]
33    Fy2 = compute_force(activation,points - dy,board=board)[1]
34
35    Fy = ((Fy1 - Fy2) / (2*delta))
36
37    Fz1 = compute_force(activation,points + dz,board=board)[2]
38    Fz2 = compute_force(activation,points - dz,board=board)[2]
39    
40    Fz = ((Fz1 - Fz2) / (2*delta))
41
42    return -1* (Fx + Fy + Fz)

def stiffness_finite_differences( activation: torch.Tensor, points: torch.Tensor, board: torch.Tensor | None = None, delta=0.001): View Source

 8def stiffness_finite_differences(activation:Tensor, points:Tensor, board:Tensor|None=None, delta= 0.001):
 9    '''
10    Computes the stiffness at a point as the gradient of the force. Force computed analytically and then finite differences used to find the gradient \n
11    Computed as `-1* (Fx + Fy + Fz)` where `Fa` is the gradient of force in that direction \n 
12    :param activation: Hologram
13    :param points: Points of interest
14    :param board: Transducers to use
15    :param delta: finite differences step size
16    
17    '''
18
19    if board is None:
20        board = TRANSDUCERS
21
22    dx = create_points(1,1,delta,0,0)
23    dy = create_points(1,1,0,delta,0)
24    dz = create_points(1,1,0,0,delta)
25
26
27
28    Fx1 = compute_force(activation,points + dx,board=board)[0]
29    Fx2 = compute_force(activation,points - dx,board=board)[0]
30
31    Fx = ((Fx1 - Fx2) / (2*delta))
32
33    Fy1 = compute_force(activation,points + dy,board=board)[1]
34    Fy2 = compute_force(activation,points - dy,board=board)[1]
35
36    Fy = ((Fy1 - Fy2) / (2*delta))
37
38    Fz1 = compute_force(activation,points + dz,board=board)[2]
39    Fz2 = compute_force(activation,points - dz,board=board)[2]
40    
41    Fz = ((Fz1 - Fz2) / (2*delta))
42
43    return -1* (Fx + Fy + Fz)

Computes the stiffness at a point as the gradient of the force. Force computed analytically and then finite differences used to find the gradient

Computed as -1* (Fx + Fy + Fz) where Fa is the gradient of force in that direction

Parameters

activation: Hologram
points: Points of interest
board: Transducers to use
delta: finite differences step size