http://www.k-wave.org/forum/topic/setnugrid-setting-non-uniform-grid-for-1d-pa-simualtion Support for the k-Wave MATLAB toolbox en-US Wed, 13 May 2026 14:19:33 +0000 http://bbpress.org/?v=1.0.2 q http://www.k-wave.org/forum/search.php http://www.k-wave.org/forum/topic/setnugrid-setting-non-uniform-grid-for-1d-pa-simualtion#post-5957 Thu, 25 May 2017 21:29:44 +0000 Bradley Treeby 5957@http://www.k-wave.org/forum/ <p>Hi Adrien,</p> <p>You could try the solution discussed in the <a href="http://www.k-wave.org/forum/topic/using-transducer-as-both-source-and-receiver-with-reflector-as-well">this post</a>. There are also some results in <a href="http://bug.medphys.ucl.ac.uk/papers/2014-Robertson-IEEEIUS.pdf">this paper</a> that might be relevant. Other than that, I can only suggest performing a convergence test so that you can have confidence in the results.</p> <p>Brad. </p> http://www.k-wave.org/forum/topic/setnugrid-setting-non-uniform-grid-for-1d-pa-simualtion#post-5945 Tue, 23 May 2017 11:45:42 +0000 langloa2 5945@http://www.k-wave.org/forum/ <p>Hi Bradley, thank you for your answer, I'll try to work with uniform grids.<br /> Do you know where I can find some tips with solid/gaseous (or any problem with high density difference at interface) photoacoustic simulation ?<br /> Best,<br /> Adrien. </p> http://www.k-wave.org/forum/topic/setnugrid-setting-non-uniform-grid-for-1d-pa-simualtion#post-5916 Mon, 08 May 2017 17:20:14 +0000 Bradley Treeby 5916@http://www.k-wave.org/forum/ <p>Hi Adrien,</p> <p>Unfortunately, while some remnants of the non-uniform grid code exist in k-Wave, this isn't a properly supported feature. We are actively working on this (e.g., <a href="https://arxiv.org/abs/1612.04156">see here</a>), but it may be a little while before we have production code that makes it into the main release.</p> <p>Brad. </p> http://www.k-wave.org/forum/topic/setnugrid-setting-non-uniform-grid-for-1d-pa-simualtion#post-5906 Thu, 27 Apr 2017 12:38:27 +0000 langloa2 5906@http://www.k-wave.org/forum/ <p>Hi all,<br /> I'm currently working on 1D photoacoustic simulation in an heterogeneous medium. The high difference in the medium properties (from solid to air) at the boundary makes the simulation go wrong.<br /> I think that setting the kgrid to non uniform (a large step away from the boundaries, and a narrow step close to them) would help me but I don't quite understand how to use the setNUgrid function.<br /> What are the different arguments of this function ? here is the beginning of my code </p> <pre><code>Nx = 1024; % number of grid points in the x (row) direction dx = 0.05e-3; % grid point spacing in the x direction [m] kgrid = makeGrid(Nx, dx); X = 0:dx:abs(Nx*dx); in = (0:pi/(width/2):2*pi).&#39;; gradient= %some gradient function ? kgrid_test = setNUGrid(kgrid,1,X,gradient,1,1);</code></pre> <p>kgrid_test is set to non uniform but with some gradient vectors tested, the parameter kgrid_test.x is still uniformly spaced.</p> <p>Best,<br /> Adrien </p>