http://www.k-wave.org/forum/topic/alpha-version-of-kwavearray-off-grid-sources Support for the k-Wave MATLAB toolbox en-US Tue, 12 May 2026 21:36:36 +0000 http://bbpress.org/?v=1.0.2 q http://www.k-wave.org/forum/search.php http://www.k-wave.org/forum/topic/alpha-version-of-kwavearray-off-grid-sources/page/2#post-8873 Fri, 28 Jul 2023 10:50:03 +0000 nhaidour 8873@http://www.k-wave.org/forum/ <p>Hi Bradley,</p> <p>I'm simulating a disc element using karray.addDiscElement, but when I draw the 3D plot of this element, it seems the shape of the element is not a disc, it looks like it's rectangle, is this normal?</p> <p>Cordially, </p> http://www.k-wave.org/forum/topic/alpha-version-of-kwavearray-off-grid-sources/page/2#post-8778 Tue, 30 May 2023 02:15:16 +0000 Jinhyuk Kim 8778@http://www.k-wave.org/forum/ <p>Thanks, Bradley!</p> <p>I have to adjust the position of the ultrasound transducer, right?</p> <p>I'll try and research successfully! </p> http://www.k-wave.org/forum/topic/alpha-version-of-kwavearray-off-grid-sources/page/2#post-8761 Thu, 18 May 2023 06:25:54 +0000 Bradley Treeby 8761@http://www.k-wave.org/forum/ <p>Hi Jinhyuk Kim,</p> <p>In <code>kWaveArray</code>, the element positions must be set in physical space (not grid space). So, in your example, there are no elements within the grid, so the mask ends up being zero (hence the error message).</p> <p>Brad </p> http://www.k-wave.org/forum/topic/alpha-version-of-kwavearray-off-grid-sources/page/2#post-8746 Thu, 27 Apr 2023 10:02:31 +0000 Jinhyuk Kim 8746@http://www.k-wave.org/forum/ <p>Hi everyone,</p> <p>I have a problem with the kspaceFirstOrder2D.</p> <p>error message is 'source.p_mask must be a binary grid with at least one element set to 1.</p> <p>I want to find acoustic fiend arising from array used kwavearray class, however, I found above error messasge.</p> <p>Here is my code.</p> <p>karray = kWaveArray;<br /> % define the grid parameters<br /> pml_size = 20;<br /> Nx = 552 - 2 * pml_size; % [grid points]<br /> Ny = 552 - 2 * pml_size; % [grid points]<br /> dx = 1e-3; % [m]<br /> dy = 1e-3; % [m]</p> <p>% create the computational grid<br /> kgrid = kWaveGrid(Nx, dx, Ny, dy);</p> <p>%% ALPHA COEFF</p> <p>medium.alpha_coeff = 0.02 * ones(Nx, Ny); % [dB/(MHz^y cm)] WATER<br /> medium.alpha_power = 1.5;</p> <p>%% SPEED<br /> medium.sound_speed = 1500 * ones(Nx, Ny); % WATER default fill! [m/s]<br /> % %skull</p> <p>%% DENSITY</p> <p>medium.density = 1000 * ones(Nx, Ny); % WATER default fill [kg/m^3]</p> <p>freq = 200*10^3; % [Hz]<br /> amp = 0.3e6; % 0.53[MPa]</p> <p>radius = 10e-3; % [m]<br /> diameter = 15e-3; % [m]<br /> focus_pos = [Nx/2, Ny/2]; % [m]</p> <p>% add arc shaped element<br /> elem_pos = [Nx/10, Ny/2]; % [m]<br /> karray.addArcElement(elem_pos, radius, diameter, focus_pos);</p> <p>% add arc shaped element<br /> elem_pos = [Nx/10, Ny/2.5]; % [m]<br /> karray.addArcElement(elem_pos, radius, diameter, focus_pos);</p> <p>% add arc shaped element<br /> elem_pos = [Nx/10, Ny/3.0]; % [m]<br /> karray.addArcElement(elem_pos, radius, diameter, focus_pos);</p> <p>source.p_mask = karray.getArrayBinaryMask(kgrid);</p> <p>display_mask = source.p_mask;</p> <p>% calculate the time step using an integer number of points per period<br /> ppw = 100; % points per wavelength<br /> cfl = 0.1; % cfl number<br /> ppp = 41; % points per period<br /> T = 1 / freq; % period [s]<br /> dt = 4e-8; % time step [s]</p> <p>% calculate the number of time steps to reach steady state<br /> t_end = 40.0575e-5;<br /> Nt = round(t_end / dt);</p> <p>% create the time array<br /> kgrid.setTime(Nt, dt);</p> <p>% define the input signal</p> <p>source.p = createCWSignals(kgrid.t_array, freq, [amp, amp, amp], 0);</p> <p>sensor.mask = ones(Nx, Ny);<br /> sensor.record = {'p', 'p_max_all'};</p> <p>% record the last 3 cycles in steady state<br /> num_periods = 15;<br /> T_points = round(num_periods * T ./ kgrid.dt);<br /> sensor.record_start_index = Nt - T_points + 1;</p> <p>% set the input arguements<br /> input_args = {'PMLInside', false,'PlotLayout', true, 'PlotPML', false, 'DisplayMask', display_mask, 'PlotScale', [-1, 1] * amp};</p> <p>% run the acoustic simulation<br /> sensor_data = kspaceFirstOrder2D(kgrid, medium, source, sensor, input_args{:});</p> <p>Thanks </p> http://www.k-wave.org/forum/topic/alpha-version-of-kwavearray-off-grid-sources/page/2#post-8745 Fri, 21 Apr 2023 06:03:48 +0000 zengqw2021 8745@http://www.k-wave.org/forum/ <p>Hi everyone,</p> <p> Is there a way for me to get grid points form part of the specified element. As for example_at_array_as_sensor.m, I got a sensor_data array of size 6748 by 1207. There is 20 elements.<br /> But, how could I tell which transducer these 6748 time series belong to.</p> <p> I find a property named 'getElementBinaryMask' may be work. But when I run it in the following way, I get an error 'Method, attribute, or field 'getElementBinaryMask' of class 'kWaveArray' not recognized.'.</p> <p>mask2 = karray.getElementBinaryMask(kgrid, 1); % grid points form part of the specified element</p> <p>Does anyone know how to solve this problem？ </p> http://www.k-wave.org/forum/topic/alpha-version-of-kwavearray-off-grid-sources/page/2#post-8673 Mon, 28 Nov 2022 15:56:34 +0000 Bradley Treeby 8673@http://www.k-wave.org/forum/ <p>Hi HN,</p> <p>Yes at the moment you need to define them manually. The <a href="http://www.k-wave.org/documentation/example_at_linear_array_transducer.php">Modelling A Linear Array Transducer Example</a> shows one way to do this.</p> <p>Brad. </p> http://www.k-wave.org/forum/topic/alpha-version-of-kwavearray-off-grid-sources/page/2#post-8672 Mon, 28 Nov 2022 13:37:46 +0000 nhaidour 8672@http://www.k-wave.org/forum/ <p>Thank you for your response ! </p> <p>I want to modelise a 2D Probe that contain elements and an inter-space element in 3D, and I think the best way is to use KwaveArray class! But I did not find the function that would allow me to declare the number of elements with an inter-space and their position. Or do I have to declare each element manually? </p> <p>Best Regards,<br /> HN </p> http://www.k-wave.org/forum/topic/alpha-version-of-kwavearray-off-grid-sources/page/2#post-8670 Tue, 22 Nov 2022 21:11:11 +0000 Bradley Treeby 8670@http://www.k-wave.org/forum/ <p>Yes - there are several examples in the included documentation under “modelling transducer arrays”. </p> http://www.k-wave.org/forum/topic/alpha-version-of-kwavearray-off-grid-sources/page/2#post-8669 Tue, 22 Nov 2022 16:12:49 +0000 nhaidour 8669@http://www.k-wave.org/forum/ <p>Hello,</p> <p>Is there some examples for using the KwaveArray ?</p> <p>Best Regards,<br /> HN </p> http://www.k-wave.org/forum/topic/alpha-version-of-kwavearray-off-grid-sources#post-8642 Tue, 08 Nov 2022 10:13:50 +0000 Bradley Treeby 8642@http://www.k-wave.org/forum/ <p>Noting that <code>kWaveArray</code> is now part of k-Wave v1.4. </p> http://www.k-wave.org/forum/topic/alpha-version-of-kwavearray-off-grid-sources#post-8573 Wed, 13 Jul 2022 17:31:30 +0000 bencox 8573@http://www.k-wave.org/forum/ <p>Hi quetaijiangchu and LewisR, </p> <p>There is not such an example yet, no, although the idea behind kWaveArray does have the capability of modelling just such sources. Essentially, given a desired surface, it is necessary to convolve it with the bandlimited interpolant, which has the form <code>sinc(x * pi / dx)</code>, and then sample the resulting function at the grid points to give the weights used in kWaveArray. The details are given in <a href="http://bug.medphys.ucl.ac.uk/papers/2019-Wise-JASA.pdf">this paper</a>. We will add more functionality in due course when we integrate it into k-Wave properly.</p> <p>Best wishes<br /> Ben </p> http://www.k-wave.org/forum/topic/alpha-version-of-kwavearray-off-grid-sources#post-8552 Wed, 15 Jun 2022 08:28:47 +0000 quetaijiangchu 8552@http://www.k-wave.org/forum/ <p>Is there an example of how to create 3D irregularities using function addCustomElement? </p> http://www.k-wave.org/forum/topic/alpha-version-of-kwavearray-off-grid-sources#post-8524 Wed, 04 May 2022 14:19:03 +0000 LewisR 8524@http://www.k-wave.org/forum/ <p>Hi Brad,</p> <p>Can kWaveArray support rectangular curved elements? Specifically curvature to both the height and width of the element. Or would this need to be done using the custom element option? I'm a little confused with how to use the addCustomElement method, would it be possible for you to do an example? If in fact it can be used to solve my problem.</p> <p>Thanks in advance,</p> <p>Lewis </p> http://www.k-wave.org/forum/topic/alpha-version-of-kwavearray-off-grid-sources#post-8211 Fri, 11 Jun 2021 21:21:05 +0000 Eric Miller 8211@http://www.k-wave.org/forum/ <p>Hi Brad, </p> <p>Works like a charm!</p> <p>Another question: I have an annular array with a rectangular central aperture. Trying to work though the kWaveArray class to see what I'll need to tweak. I have my ring inner and outer diameters, I only need to remove the parts of the rings that overlap with the rectangular aperture. Any guidance on doing this such that the grid weights come out correct? </p> <p>-Eric </p> http://www.k-wave.org/forum/topic/alpha-version-of-kwavearray-off-grid-sources#post-8203 Thu, 10 Jun 2021 09:22:46 +0000 Bradley Treeby 8203@http://www.k-wave.org/forum/ <p>Hi Eric,</p> <p>I've just up-dated the linked file with the missing function. Note, <code>focusedAnnulusONeil</code> requires an updated version of <code>focusedBowlONeil</code> that also returns the complex pressure, so I've added that also.</p> <p>Let me know any problems!</p> <p>Brad. </p> http://www.k-wave.org/forum/topic/alpha-version-of-kwavearray-off-grid-sources#post-8201 Wed, 09 Jun 2021 17:40:43 +0000 Eric Miller 8201@http://www.k-wave.org/forum/ <p>Hi Brad, k-wave team,</p> <p>Thanks so much for the annular array support! It helps my work quite a bit, really awesome work.</p> <p>Could the 0.3 kArray Alpha package be missing the function "focusedAnnulusOneil.m"? I have "focusedBowlOneil.m" as a part of k-wave 1.3, but I don't see the annulus code in either the k-wave 1.3 or kArray 0.3 downloads and "ex08_focused_annular_array_3D.m" calls that function. I may very well be missing it.</p> <p>Thanks again,<br /> Eric </p> http://www.k-wave.org/forum/topic/alpha-version-of-kwavearray-off-grid-sources#post-8174 Tue, 08 Jun 2021 14:44:12 +0000 Bradley Treeby 8174@http://www.k-wave.org/forum/ <p>@Kris: Unfortunately, there is currently no good way to use kWaveArray with time reversal. This is because time reversal uses the <code>source.p_mode = &#39;dirichlet&#39;</code> option, and that doesn't make much sense when the source mask is non-local. I'll give it some thought.</p> <p>@Zeng: It's just a matter of adding the downloaded folder to the MATLAB path. What error message do you get? </p> http://www.k-wave.org/forum/topic/alpha-version-of-kwavearray-off-grid-sources#post-8172 Mon, 07 Jun 2021 16:15:11 +0000 zengqw2021 8172@http://www.k-wave.org/forum/ <p>Dear all,<br /> I copy the alpha codes to my installation path of k-Wave:"\k-Wave\ " and "k-Wave\private". I tried to run a example, but it doesn't work. Does anyone know how this bag works?<br /> Cheers<br /> Zeng </p> http://www.k-wave.org/forum/topic/alpha-version-of-kwavearray-off-grid-sources#post-8161 Mon, 31 May 2021 16:08:06 +0000 kdreher 8161@http://www.k-wave.org/forum/ <p>Hi everyone,<br /> I really like the new kWaveArray class, so thank you very much for that!</p> <p>However, I wondered how to use it in combination with the time reversal reconstruction? It doesn't seem to work the same way as before since the number of time series doesn't match the number of source elements in the sensor mask anymore.</p> <p>Is there some method that does the inverse of the combineSensorData method?</p> <p>Cheers,<br /> Kris </p> http://www.k-wave.org/forum/topic/alpha-version-of-kwavearray-off-grid-sources#post-7899 Sun, 01 Nov 2020 22:27:37 +0000 Bradley Treeby 7899@http://www.k-wave.org/forum/ <p>Hi Frank,</p> <p>This is a bug - thanks for reporting. In all cases it should be <code>element_num</code>. New download link with bug fix in the original post above.</p> <p>Applying the affine transform won't work here (these are angles, rather than a position as in the other elements). I've left it as an issue for now. What needs to happen is the angles extracted from the affine transform, and these angles added to the individual element angles.</p> <p>Brad. </p>