k-Wave

1. ChiaChin Li
   

   Member
   Joined: Mar '11
   Posts: 5

   hi,

   I want to make a heterogeneous medium simulation with sensors of Gaussian freq response. but once i add sensor.frequency_response into my simulation, there will be a error about dimensions mismatch:
   Error in ==> kspaceFirstOrder_filterSensorData at 41
   sensor_data = fft(sensor_data, [], 2).*repmat([gauss, flipud(gauss)], length(sensor_data(:, 1)), 1);
   Could you tell me how to solve this problem?

   Thanks a lot!
   Chia-Chin

   Posted 13 years ago #

2. Bradley Treeby
   

   Developer
   Joined: Mar '10
   Posts: 1,643

   Hi Chia-Chin,

   Thanks for your post. Are you doing a simulation in 1, 2, or 3D? What are your inputs? What version of MATLAB and k-Wave are you using?

   If you try adding the line

   sensor.frequency_response = [2e6, 100];

   to the Initial Value Problems -> Heterogeneous Propagation Medium Example just before running the simulation, do you also get the same error?

   Brad.

   Posted 13 years ago #

3. ChiaChin Li
   

   Member
   Joined: Mar '11
   Posts: 5

   Hi Bradley,

   I do simulation modified from eterogeneous Propagation Medium Example. And I use MATLAB 7.10.0 (R2010a) and k-Wave toolbox b03.

   I tried adding the line you said

   sensor.frequency_response = [2e6, 100];

   to Heterogeneous Propagation Medium Example. It could work successfully.
   And I tried to add those lines:

   fs = 200e6; % [Hz]
   dt = 1/fs;
   t_end = 604*2*dt;
   kgrid.t_array = 0:dt:t_end;

   to fix sampling rate. Then the error showed up again. In the Heterogeneous Propagation Medium Example, the size of sensor_data is 50x608. And one of the line I mention before:

   t_end = 604*2*dt;

   Once the number multiply dt over 607, the error will occur. But I need longer kgrid.t_array to record the simulation result.
   Hope you can help me to solve those problem.

   Thanks!
   Chia-Chin

   Posted 13 years ago #

4. Bradley Treeby
   

   Developer
   Joined: Mar '10
   Posts: 1,643

   Hi Chia-Chin,

   It seems there is a bug in kspaceFirstOrder_filterSensorData when kgrid.t_array has an odd number of time points. You can download an updated version from here:

   kspaceFirstOrder_filterSensorData.m

   Try downloading the function and replacing the existing one in the private folder in the k-Wave Toolbox. Alternatively, as a work around you could force kgrid.t_array to have an even number of time points.

   Let me know if this fixes the problem for you.

   Thanks,

   Brad.

   Posted 13 years ago #

5. ChiaChin Li
   

   Member
   Joined: Mar '11
   Posts: 5

   Hi Bradley,

   After replace the kspaceFirstOrder_filterSensorData.m file, it can work as I expect.

   Thank you very much!

   Best Regard.
   Chia-Chin

   Posted 13 years ago #

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