http://www.k-wave.org/forum/topic/normalisation-factors Support for the k-Wave MATLAB toolbox en-US Wed, 13 May 2026 03:09:29 +0000 http://bbpress.org/?v=1.0.2 q http://www.k-wave.org/forum/search.php http://www.k-wave.org/forum/topic/normalisation-factors#post-8097 Thu, 25 Mar 2021 16:57:02 +0000 Bradley Treeby 8097@http://www.k-wave.org/forum/ <p>Hi Olya,</p> <p>The result in k-Wave is not normalised, but the analytical Green's function has a singularity at the origin.</p> <p>Have a look at the time varying source examples to see how to define the time input.</p> <p>Brad. </p> http://www.k-wave.org/forum/topic/normalisation-factors#post-8063 Fri, 12 Feb 2021 11:45:11 +0000 olya 8063@http://www.k-wave.org/forum/ <p>Hi Bradley,</p> <p>Thanks a lot for your feedback and for providing the paper! </p> <p>I would have two additional questions to that. If I understand correctly in order to be able to compare Green's function calculated in kWave and analytically I would have to normalise amplitude of the analytical solution to 1, at 1 mm distance as it was described in your paper? and in kWave it is normalised on default? </p> <p>And could you explain me please how can define the time propagator correctly? As I understand, it is no the initial pulse itself? And how can I control it in kWave?</p> <p>Many thanks,<br /> Olga </p> http://www.k-wave.org/forum/topic/normalisation-factors#post-8047 Sat, 06 Feb 2021 12:29:17 +0000 Bradley Treeby 8047@http://www.k-wave.org/forum/ <p>Hi Olga, </p> <p>If you're trying to compare with theoretical decay with distance (for example, as shown in Fig. 1 of <a href="http://bug.medphys.ucl.ac.uk/papers/2018-Treeby-JASA.pdf">this paper</a>), you will need to choose a point close to the source to perform the normalisation.</p> <p>Are you referring to filtering an initial pressure distribution or a time series? In any case, you are free to filter the signal however you like.</p> <p>Brad </p> http://www.k-wave.org/forum/topic/normalisation-factors#post-8038 Tue, 02 Feb 2021 10:46:03 +0000 olya 8038@http://www.k-wave.org/forum/ <p>Hi !</p> <p>I am trying to check the simulated field by kWave with field simulated by Green's function in water. </p> <p>In some literature the Green's function is normalised by the factor j*omega*rho*Q = 1 modelling in this way the source with frequency independent volume acceleration, and the factor 4*pi in denominator can be absent. Could you tell me please what normalisations to the Green's function should be made while comparing it with kWave?</p> <p>And one more question about filtering. Can other filtering be used, with Turkey window for example?</p> <p>Best wishes,<br /> Olga </p>