k-Wave User Forum » Topic: how to define source.p as a matrix

k-Wave User Forum » Topic: how to define source.p as a matrix http://www.k-wave.org/forum/topic/how-to-define-sourcep-as-a-matrix Support for the k-Wave MATLAB toolbox en-US Wed, 13 May 2026 01:00:08 +0000 http://bbpress.org/?v=1.0.2 <![CDATA[Search]]> q http://www.k-wave.org/forum/search.php Bradley Treeby on "how to define source.p as a matrix" http://www.k-wave.org/forum/topic/how-to-define-sourcep-as-a-matrix#post-7939 Thu, 26 Nov 2020 11:25:33 +0000 Bradley Treeby 7939@http://www.k-wave.org/forum/ Do you mean how can you remap results from an axisymmetric simulation to 3D? You could use something like <code>revolve2D</code>. Brad HustYjq on "how to define source.p as a matrix" http://www.k-wave.org/forum/topic/how-to-define-sourcep-as-a-matrix#post-7914 Tue, 03 Nov 2020 08:42:13 +0000 HustYjq 7914@http://www.k-wave.org/forum/ Hi Bradley Treeby， I want to perform a axisymmetric simulations in 3D.I have a two-dimensional matrices, and i want to rotate around an axis like the example "Simulations In An Axisymmetric Coordinate System Example" .But I want to get a three-dimensional body instead of a two-dimensional plane.Every gp in the body has value.Can i do this in K-wave? Thank you! Bradley Treeby on "how to define source.p as a matrix" http://www.k-wave.org/forum/topic/how-to-define-sourcep-as-a-matrix#post-7907 Sun, 01 Nov 2020 22:59:14 +0000 Bradley Treeby 7907@http://www.k-wave.org/forum/ Hi HustYjq, What do you mean by wrong waveform? If you can post a small working example and let me know exactly what the problem is, I'll take a look. Brad. HustYjq on "how to define source.p as a matrix" http://www.k-wave.org/forum/topic/how-to-define-sourcep-as-a-matrix#post-7884 Mon, 19 Oct 2020 15:19:50 +0000 HustYjq 7884@http://www.k-wave.org/forum/ Hi, I have an matrix 40 *100 of initial pressure .In some locations the pressure is not 0.And I define the source.mask as source.p_mask(12:27,1:45)=1;But I have wrong Waveform.Can anyone tell me how to solve these problem? Nx = 40; % number of grid points in the x (row) direction Ny = 100; % number of grid points in the y (column) direction dx = 0.1e-3; % grid point spacing in the x direction [m] dy = 0.1e-3; % grid point spacing in the y direction [m] kgrid = kWaveGrid(Nx, dx, Ny, dy); p1 = resize(p0, [Nx, Ny]); medium.sound_speed = 1500; % [m/s] medium.alpha_coeff = 0.75; % [dB/(MHz^y cm)] medium.alpha_power = 1.5; kgrid.makeTime(medium.sound_speed); source.p_mask = zeros(Nx, Ny); source.p_mask(12:27,1:45)=1; j=1; for k = 1:45; for i = 12:27; source.p(j,:)= p1(i,k) *(heaviside(kgrid.t_array); j=j+1; end end HustYjq on "how to define source.p as a matrix" http://www.k-wave.org/forum/topic/how-to-define-sourcep-as-a-matrix#post-7883 Mon, 19 Oct 2020 15:19:48 +0000 HustYjq 7883@http://www.k-wave.org/forum/ Hi, I have an matrix 40 *100 of initial pressure .In some locations the pressure is not 0.And I define the source.mask as source.p_mask(12:27,1:45)=1;But I have wrong Waveform.Can anyone tell me how to solve these problem? Nx = 40; % number of grid points in the x (row) direction Ny = 100; % number of grid points in the y (column) direction dx = 0.1e-3; % grid point spacing in the x direction [m] dy = 0.1e-3; % grid point spacing in the y direction [m] kgrid = kWaveGrid(Nx, dx, Ny, dy); p1 = resize(p0, [Nx, Ny]); medium.sound_speed = 1500; % [m/s] medium.alpha_coeff = 0.75; % [dB/(MHz^y cm)] medium.alpha_power = 1.5; kgrid.makeTime(medium.sound_speed); source.p_mask = zeros(Nx, Ny); source.p_mask(12:27,1:45)=1; j=1; for k = 1:45; for i = 12:27; source.p(j,:)= p1(i,k) *(heaviside(kgrid.t_array); j=j+1; end end Bradley Treeby on "how to define source.p as a matrix" http://www.k-wave.org/forum/topic/how-to-define-sourcep-as-a-matrix#post-7860 Wed, 30 Sep 2020 09:21:57 +0000 Bradley Treeby 7860@http://www.k-wave.org/forum/ Hi HustYjq, I'd suggest working through the time varying source examples in the toolbox (you can access these using the MATLAB help browser), and the k-Wave user manual. These should tell you everything you need. Let me know if you get stuck on something specific after taking a look at these. Brad. HustYjq on "how to define source.p as a matrix" http://www.k-wave.org/forum/topic/how-to-define-sourcep-as-a-matrix#post-7859 Wed, 30 Sep 2020 09:17:01 +0000 HustYjq 7859@http://www.k-wave.org/forum/ well,i modified my code ,but it still has problem:Input signal must be a vector. p0_magnitude = 1; p0 = p0_magnitude * loadImage('150mev.png'); % create the computational grid Nx = 128; % number of grid points in the x (row) direction Ny = 128; % number of grid points in the y (column) direction dx = 0.1e-3; % grid point spacing in the x direction [m] dy = 0.1e-3; % grid point spacing in the y direction [m] kgrid = kWaveGrid(Nx, dx, Ny, dy); % create the time array % resize the image to match the size of the computational grid and assign % to the source input structure p1 = resize(p0, [Nx, Ny]); % define the properties of the propagation medium medium.sound_speed = 1500; % [m/s] medium.alpha_coeff = 0.75; % [dB/(MHz^y cm)] medium.alpha_power = 1.5; source.p_mask = ones(Nx, Ny); kgrid.makeTime(medium.sound_speed); % define a time varying sinusoidal source source_freq = 0.25e6; % [Hz] j=1; for i = 1:128 % for k = 1:128 source.p(j,:)= p1(i,k) * sin(2 * pi * source_freq * kgrid.t_array); j=j+1; end end % [Pa] % filter the source to remove high frequencies not supported by the grid source.p = filterTimeSeries(kgrid, medium, source.p); HustYjq on "how to define source.p as a matrix" http://www.k-wave.org/forum/topic/how-to-define-sourcep-as-a-matrix#post-7858 Wed, 30 Sep 2020 03:23:30 +0000 HustYjq 7858@http://www.k-wave.org/forum/ Hi， Can anyone tell me how to define source.p as a matrix? I load the image and get the source.p0 as a matrix.But i don't know how to define source.p as a martix with the same size as source.p0. p0_magnitude = 1; p0 = p0_magnitude * loadImage('150mev.png'); % create the computational grid Nx = 128; % number of grid points in the x (row) direction Ny = 128; % number of grid points in the y (column) direction dx = 0.1e-3; % grid point spacing in the x direction [m] dy = 0.1e-3; % grid point spacing in the y direction [m] kgrid = kWaveGrid(Nx, dx, Ny, dy); % resize the image to match the size of the computational grid and assign % to the source input structure source.p0 = resize(p0, [Nx, Ny]); % define the properties of the propagation medium medium.sound_speed = 1500; % [m/s] medium.alpha_coeff = 0.75; % [dB/(MHz^y cm)] medium.alpha_power = 1.5; % define a time varying sinusoidal source source_freq = 0.25e6; % [Hz] for i = 1:128 % for k = 1:128 source.mag = source.p0(i,k) % source.p = source.mag * sin(2 * pi * source_freq * kgrid.t_array); end end % [Pa] % filter the source to remove high frequencies not supported by the grid source.p = filterTimeSeries(kgrid, medium, source.p);