http://www.k-wave.org/forum/topic/weird-results-when-modeling-attenuation-with-the-gpu-and-cpu-versions Support for the k-Wave MATLAB toolbox en-US Tue, 12 May 2026 22:24:15 +0000 http://bbpress.org/?v=1.0.2 q http://www.k-wave.org/forum/search.php http://www.k-wave.org/forum/topic/weird-results-when-modeling-attenuation-with-the-gpu-and-cpu-versions#post-8914 Thu, 21 Sep 2023 11:45:05 +0000 djps 8914@http://www.k-wave.org/forum/ <p>perhaps you could just say how the perfectly matched layers were constructed in the benchmarks? </p> http://www.k-wave.org/forum/topic/weird-results-when-modeling-attenuation-with-the-gpu-and-cpu-versions#post-8850 Thu, 29 Jun 2023 08:32:14 +0000 djps 8850@http://www.k-wave.org/forum/ <p>That would be great, thanks! </p> http://www.k-wave.org/forum/topic/weird-results-when-modeling-attenuation-with-the-gpu-and-cpu-versions#post-8786 Fri, 02 Jun 2023 08:50:26 +0000 Bradley Treeby 8786@http://www.k-wave.org/forum/ <p>Hi djps,</p> <p>I'll tidy up all the k-Wave intercomparison code when I get a chance and move to a public GitHub repo.</p> <p>Brad. </p> http://www.k-wave.org/forum/topic/weird-results-when-modeling-attenuation-with-the-gpu-and-cpu-versions#post-8785 Wed, 31 May 2023 14:23:43 +0000 djps 8785@http://www.k-wave.org/forum/ <p>Is there an example of how to generate the kwave results for the benchmark data, rather than download it? </p> http://www.k-wave.org/forum/topic/weird-results-when-modeling-attenuation-with-the-gpu-and-cpu-versions#post-8732 Thu, 16 Mar 2023 10:22:33 +0000 CelestineAngla 8732@http://www.k-wave.org/forum/ <p>Makes sense, thank you very much for your answer ! </p> http://www.k-wave.org/forum/topic/weird-results-when-modeling-attenuation-with-the-gpu-and-cpu-versions#post-8731 Wed, 15 Mar 2023 19:55:52 +0000 Bradley Treeby 8731@http://www.k-wave.org/forum/ <p>If your source has a single frequency, the frequency dependent power law can be set to anything, as long as the value for alpha_coeff is adjusted accordingly to give the correct absorption in dB/cm. To avoid dispersion, you can set alpha_power to 2. This is the approach I used for the intercomparison simulations.</p> <p>The code used is the same one as publicly available, except for the very large 3D simulations which were done using the MPI code. </p> http://www.k-wave.org/forum/topic/weird-results-when-modeling-attenuation-with-the-gpu-and-cpu-versions#post-8730 Wed, 15 Mar 2023 14:41:16 +0000 CelestineAngla 8730@http://www.k-wave.org/forum/ <p>Please, does anyone know how absorption was modeled in the benchmark configurations of the paper "Benchmark problems for transcranial ultrasound simulation" ?<br /> Is it possible to model absorption without dispersion with the 3D version of k-Wave optimized for high performance computing clusters ?<br /> Thank you </p> http://www.k-wave.org/forum/topic/weird-results-when-modeling-attenuation-with-the-gpu-and-cpu-versions#post-8704 Fri, 10 Feb 2023 12:06:44 +0000 CelestineAngla 8704@http://www.k-wave.org/forum/ <p>I have another question : in the paper "Benchmark problems for transcranial ultrasound simulation:<br /> Intercomparison of compressional wave models" by Aubry et al., I read that you used a 3D version of k-Wave optimized for high performance computing clusters, is it based on the same C++ code as kspaceFirstOrder3DC and kspaceFirstOrder3DG ?<br /> In this paper, did you modeled only absorption without dispersion ? If so, how did you do it ?</p> <p>Thank you. </p> http://www.k-wave.org/forum/topic/weird-results-when-modeling-attenuation-with-the-gpu-and-cpu-versions#post-8701 Wed, 01 Feb 2023 17:49:04 +0000 CelestineAngla 8701@http://www.k-wave.org/forum/ <p>If the C++ code does not support alpha_mode inputs then I guess it is impossible to model a medium with absorption and without dispersion ? </p> http://www.k-wave.org/forum/topic/weird-results-when-modeling-attenuation-with-the-gpu-and-cpu-versions#post-8700 Wed, 01 Feb 2023 17:43:44 +0000 CelestineAngla 8700@http://www.k-wave.org/forum/ <p>Thank you for your quick answer.</p> <p>I didn't know that the C++ code didn't support the alpha_mode. As I set it usually to "no_dispersion", I guess this is the reason why the results are so weird (probably numerically unstable). </p> <p>But as the GPU version works for configurations where alpha_coeff = 0.001 for the whole computation zone, does it means that dispersion is only taken into account when alpha_coeff is set to another value for the medium of interest ? How does alpha_coeff affect the dispersion computation ?</p> <p>I don't know how to provide you my source field and computation zone through this forum, but I do simulations through a homogeneous medium with rho=1600kg/m3 and c=2400m/s at a frequency around 1MHz. </p> http://www.k-wave.org/forum/topic/weird-results-when-modeling-attenuation-with-the-gpu-and-cpu-versions#post-8694 Fri, 13 Jan 2023 00:29:53 +0000 Bradley Treeby 8694@http://www.k-wave.org/forum/ <p>Could you post a small example that reproduces the problem? Note, the C++ codes don’t support the alpha_mode inputs. </p> http://www.k-wave.org/forum/topic/weird-results-when-modeling-attenuation-with-the-gpu-and-cpu-versions#post-8693 Thu, 12 Jan 2023 15:06:29 +0000 CelestineAngla 8693@http://www.k-wave.org/forum/ <p>Hi, </p> <p>I have been running simulations with the kspaceFirstOrder3D solver and with the CPU and GPU versions (kspaceFirstOrder3DC and kspaceFirstOrder3DG) and it works well.</p> <p>But when I add attenuation to the medium (using medium.alpha_coeff), kspaceFirstOrder3D returns the expected result while the CPU and GPU versions return very weird fields that are nearly zero everywhere except around one location.</p> <p>Do you have any ideas on what the problem could be ?</p> <p>Thank you,</p> <p>Célestine Angla </p>