shanchengbao09tamuedu Support for the k-Wave MATLAB toolbox en-US Wed, 13 May 2026 00:22:33 +0000 http://bbpress.org/?v=1.0.2 q http://www.k-wave.org/forum/search.php http://www.k-wave.org/forum/topic/the-plotlayout-from-kaspacefirstorder2d#post-8447 Tue, 01 Feb 2022 10:19:18 +0000 Bradley Treeby 8447@http://www.k-wave.org/forum/ <p>The domain in this example includes the PML, while the plot doesn't. If you include the PML in the plot (set <code>&#39;PlotPML&#39;, true</code>) it should give you what you expect. </p> http://www.k-wave.org/forum/topic/how-to-interpret-the-wavenumber-component-vector#post-8434 Sat, 22 Jan 2022 12:09:48 +0000 chiragjin 8434@http://www.k-wave.org/forum/ <p>I am also a beginner in this space and came across the following youtube video some days back. It provides a practical feel of how wavenumber works. Hope it helps.</p> <p><a href="https://www.youtube.com/watch?v=02J_j6SWH_M&amp;list=PLUoFce-1LZKqaSpFtHUSaGYBebmEmitFj&amp;index=7&amp;ab_channel=BE280A" rel="nofollow">https://www.youtube.com/watch?v=02J_j6SWH_M&amp;list=PLUoFce-1LZKqaSpFtHUSaGYBebmEmitFj&amp;index=7&amp;ab_channel=BE280A</a></p> <p>Chirag </p> http://www.k-wave.org/forum/topic/the-plotlayout-from-kaspacefirstorder2d#post-8432 Wed, 19 Jan 2022 19:09:53 +0000 shanchengbao09@tamu.edu 8432@http://www.k-wave.org/forum/ <p>I am confused by the figure output on the webpage<br /> <a href="http://www.k-wave.org/documentation/example_ivp_heterogeneous_medium.php" rel="nofollow">http://www.k-wave.org/documentation/example_ivp_heterogeneous_medium.php</a><br /> I don't understand why the proportion of the white bar in the forth panel (Density) of Figure 1 is not 1/4 of the whole area. </p> <p>If the medium.density is set using the following formulas, one fourth of the medium is 1000, and three fourths are 1200:</p> <p>medium.density = 1000 * ones(Nx, Ny); % [kg/m^3]<br /> medium.density(:, Ny/4:Ny) = 1200; % [kg/m^3]</p> <p>In the output figure generated by:<br /> sensor_data = kspaceFirstOrder2D(kgrid, medium, source, sensor, 'PlotLayout', true, 'PlotPML', false), I expect one-forth of the Density output is white, and three-fourths are dark. However, the figure on that page is not like this, it seems the white part is too narrow. I tried the code myself, and the result also indicates that the white part is too narrow. </p> http://www.k-wave.org/forum/topic/how-to-interpret-the-wavenumber-component-vector#post-8428 Fri, 14 Jan 2022 21:01:37 +0000 shanchengbao09@tamu.edu 8428@http://www.k-wave.org/forum/ <p>Thanks so much. I think I understand it now </p> http://www.k-wave.org/forum/topic/how-to-interpret-the-wavenumber-component-vector#post-8423 Thu, 13 Jan 2022 14:09:29 +0000 Bradley Treeby 8423@http://www.k-wave.org/forum/ <p>Imagine taking a signal containing a sine wave with single spatial frequency (wavenumber). If you take a Fourier transform of the signal, you will see a peak at the frequency of the sine wave. The wavenumber vector you describe essentially specifies the frequency axis of the Fourier transform. The actual wavenumbers present will depend on the waves present in the signal.</p> <p>Hope that helps,</p> <p>Brad. </p> http://www.k-wave.org/forum/topic/how-to-interpret-the-wavenumber-component-vector#post-8420 Sun, 09 Jan 2022 23:53:14 +0000 shanchengbao09@tamu.edu 8420@http://www.k-wave.org/forum/ <p>I am a rookie in K-Wave. Pretty confused by the definition and formula of wavenumber component vector:<br /> To my understand, wavenumber is defined as the number of radians per unit distance: 2*pi/WaveLength. However, in the kWaveGrid.m, kx_vec = (2*pi/dx) .* nx, where dx is the grid size, nx is an array from -0.5 to +0.5. How is the output kx_vec relate to the number of radians per unit distance?</p> <p>Appreciate if anyone can provide a general explanation to this point or provide some reading materials. Thanks so much </p>