http://www.k-wave.org/forum/topic/time-reversal-reconstruction Support for the k-Wave MATLAB toolbox en-US Wed, 13 May 2026 01:05:10 +0000 http://bbpress.org/?v=1.0.2 q http://www.k-wave.org/forum/search.php http://www.k-wave.org/forum/topic/time-reversal-reconstruction#post-5423 Thu, 17 Mar 2016 13:19:06 +0000 Bradley Treeby 5423@http://www.k-wave.org/forum/ <p>Hi Bernhard,</p> <p>As mentioned above, you can use the C++ code directly for time reversal, but you need to manually reverse your recorded boundary data, and then use this as a Dirichlet source in your simulation. In steps:</p> <p>(1) Instead of assigning your boundary data to <code>sensor.time_reversal_boundary_data</code>, reverse it in time and assign to <code>source.p</code>, i.e.,</p> <p><code>source.p = flipdim(boundary_data, 2);</code></p> <p>(2) Set the source to be a Dirichlet boundary condition</p> <p><code>source.p_mode = &#39;dirichlet&#39;;</code></p> <p>(3) Instead of assigning the position of your detectors to <code>sensor.mask</code>, assign it to <code>source.p_mask</code></p> <p>(4) Set <code>sensor.record = {&#39;p_final&#39;}</code> to record the final (i.e., reconstructed) pressure field. The sensor mask isn't used in this case, so anything will do. Your reconstructed image will be contained in the field <code>sensor_data.p_final</code></p> <p>If you are stuck on how to get started with time-reversal using the normal syntax, there are several examples included in the toolbox.</p> <p>Hope that helps,</p> <p>Brad. </p> http://www.k-wave.org/forum/topic/time-reversal-reconstruction#post-5404 Fri, 26 Feb 2016 15:59:37 +0000 bernhardkaplan 5404@http://www.k-wave.org/forum/ <p>Hi,<br /> I would like to use k-wave's C++ code on a compute cluster without matlab via the command line and to do time-reversal reconstruction instead of FFT, but I am not able to create the HDF5 files using <code>kspaceFirstOrder3D(kgrid, medium, source, sensor, &#39;SaveToDisk&#39;, filename);</code></p> <p>When looking at <code>kspaceFirstOrder3DC.m</code> <code>time_rev</code> is set to true if the sensor has a <code>time_reversal_boundary_data</code> field -- however, when calling the kspaceFirstOrder3D function, an error is raised with the message "The optional input 'SaveToDisk' is currently only compatible with forward simulations using a non-zero binary sensor mask", but the sensor mask is non-zero.</p> <p>Could you explain in more detail how to use the C++ for time-reversal reconstruction instead of FFT? An example script would be fantastic (I was using the <code>example_pr_3D_TR_planar_sensor.m</code> as starting point so far).</p> <p>Many thanks in advance and best regards,<br /> Bernhard Kaplan </p> http://www.k-wave.org/forum/topic/time-reversal-reconstruction#post-2028 Thu, 04 Apr 2013 08:51:30 +0000 Bradley Treeby 2028@http://www.k-wave.org/forum/ <p>Hi Chao,</p> <p>The original method of using time-reversal (i.e., setting <code>sensor.time_reversal_boundary_data</code>) is not included in the C++ code. However, you can use time-reversal in the more general way of reversing the recorded boundary data and applying it as a Dirichlet boundary condition. If you look inside the function <code>kspaceFirstOrder3DC</code>, you can see an example of how this is done. The net result is the same via both methods.</p> <p>Brad. </p> http://www.k-wave.org/forum/topic/time-reversal-reconstruction#post-2027 Thu, 04 Apr 2013 01:54:47 +0000 huangchao 2027@http://www.k-wave.org/forum/ <p>Hi,</p> <p>It seems that the time-reversal reconstruction is not available in the current release of the C++ code. Is this right? I just want to confirm.</p> <p>Thanks,<br /> Chao </p>