k-Wave User Forum » Topic: Single Slit Diffraction

k-Wave User Forum » Topic: Single Slit Diffraction http://www.k-wave.org/forum/topic/single-slit-diffraction Support for the k-Wave MATLAB toolbox en-US Wed, 13 May 2026 00:06:30 +0000 http://bbpress.org/?v=1.0.2 <![CDATA[Search]]> q http://www.k-wave.org/forum/search.php Paulinetolen on "Single Slit Diffraction" http://www.k-wave.org/forum/topic/single-slit-diffraction#post-5051 Thu, 23 Apr 2015 16:26:21 +0000 Paulinetolen 5051@http://www.k-wave.org/forum/ Brad, Wow! I overlooked that entire folder. Thank you so much Bradley Treeby on "Single Slit Diffraction" http://www.k-wave.org/forum/topic/single-slit-diffraction#post-5050 Thu, 23 Apr 2015 09:31:30 +0000 Bradley Treeby 5050@http://www.k-wave.org/forum/ Hi Pauline, What is the error message you receive? You can access vanilla versions of all the examples without needing to copy and paste them via the MATLAB help browser (see Sec. 1.4 in the k-Wave manual). These should run without errors. Brad. Anthony on "Single Slit Diffraction" http://www.k-wave.org/forum/topic/single-slit-diffraction#post-5049 Tue, 21 Apr 2015 13:54:52 +0000 Anthony 5049@http://www.k-wave.org/forum/ Hi Pauline, I didn't try to run your code but you might have a problem because of the very strong heterogeneity. See the topic entitled "A Question about The Reflection at The Hetrogeneous Media Boundary" for more details. Hope it helps :-) Anthony Paulinetolen on "Single Slit Diffraction" http://www.k-wave.org/forum/topic/single-slit-diffraction#post-5047 Sat, 18 Apr 2015 20:47:08 +0000 Paulinetolen 5047@http://www.k-wave.org/forum/ I'm new to this toolbox and I'm working through some of the simulatons. I tried copy pasting the examples and the ones I tried worked until I tried to run the Single Slit Diffusion. Could anyone look at my code and tell me what I'm doing wrong? ===================================================================== %%%%% load homogenous Propogation Medium % define the properties used in the simulation p0 = 7*10^6; % source pressure [Pa] c0 = 1500; % sound speed [m/s] rho0 = 1000; % density [kg/m^3] alpha_0 = 0.25; % absorption coefficient [dB/(MHz^2 cm)] sigma = 1; % shock parameter source_freq = 1e6; % frequency [Hz] points_per_wavelength = 50; % number of grid points per wavelength at f0 wavelength_separation = 15; % separation between the source and detector PML_size = 64; % PML size CFL = 0.25; % % 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 = makeGrid(Nx, dx, Ny, dy); % 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 the ratio between the barrier and background sound speed and density barrier_scale = 20; % create the time array using the barrier sound speed t_end = 40e-6; % [s] CFL = 0.5; % Courantâ€“Friedrichsâ€“Lewy number kgrid.t_array = makeTime(kgrid, c0*barrier_scale, CFL, t_end); % create a mask of a barrier with a slit slit_thickness = 2; % [grid points] slit_width = 10; % [grid points] slit_x_pos = Nx - Nx/4; % [grid points] slit_offset = Ny/2 - slit_width/2 - 1; % [grid points] slit_mask = zeros(Nx, Ny); slit_mask(slit_x_pos:slit_x_pos + slit_thickness, 1:1 + slit_offset) = 1; slit_mask(slit_x_pos:slit_x_pos + slit_thickness, end - slit_offset:end) = 1; % assign the slit to the properties of the propagation medium medium.sound_speed = c0*ones(Nx, Ny); medium.density = rho0*ones(Nx, Ny); medium.sound_speed(slit_mask == 1) = barrier_scale*c0; medium.density(slit_mask == 1) = barrier_scale*rho0; % define a centered circular sensor sensor_radius = 4e-3; % [m] num_sensor_points = 50; sensor.mask = makeCartCircle(sensor_radius, num_sensor_points); % create time array t_end = 3e-5; kgrid.t_array = makeTime(kgrid, medium.sound_speed, [], t_end); % define four sensor points centered about source.p0 sensor_radius = 40; % [grid points] sensor.mask = zeros(Nx, Ny); sensor.mask(Nx/2 + sensor_radius, Ny/2) = 1; sensor.mask(Nx/2 - sensor_radius, Ny/2) = 1; sensor.mask(Nx/2, Ny/2 + sensor_radius) = 1; sensor.mask(Nx/2, Ny/2 - sensor_radius) = 1; % define a single source point source.p_mask = zeros(Nx, Ny); source.p_mask(end - Nx/4, Ny/2) = 1; % define a time varying sinusoidal source source_freq = 0.25e6; % [Hz] source_mag = 2; % [Pa] source.p = source_mag*sin(2*pi*source_freq*kgrid.t_array); % filter the source to remove high frequencies not supported by the grid source.p = filterTimeSeries(kgrid, medium, source.p); % define a curved transducer element source.p_mask = makeCircle(Nx, Ny, 61, 61, 60, pi/2); % define a time varying sinusoidal source source_freq = 0.25e6; % [Hz] source_mag = 0.5; % [Pa] source.p = source_mag*sin(2*pi*source_freq*kgrid.t_array); % filter the source to remove any high frequencies not supported by the grid source.p = filterTimeSeries(kgrid, medium, source.p); % create a sensor mask covering the entire computational domain using the % opposing corners of a rectangle sensor.mask = [1, 1, Nx, Ny].'; % set the record mode to capture the final wave-field and the statistics at % each sensor point sensor.record = {'p_final', 'p_max', 'p_rms'}; % set the input options input_args = {'PMLInside', false, 'PMLSize', PML_size, 'PlotPML', false, ... 'DisplayMask', slit_mask, 'DataCast', 'single'}; % run the simulation sensor_data = kspaceFirstOrder2D(kgrid, medium, source, sensor, input_args{:}); ================================================================ Thank you! Pauline