http://www.k-wave.org/forum/topic/data-loading-failed Support for the k-Wave MATLAB toolbox en-US Wed, 13 May 2026 15:47:55 +0000 http://bbpress.org/?v=1.0.2 q http://www.k-wave.org/forum/search.php http://www.k-wave.org/forum/topic/data-loading-failed#post-6093 Sun, 06 Aug 2017 14:33:53 +0000 Bradley Treeby 6093@http://www.k-wave.org/forum/ <p>Hi Gaoyang,</p> <p>Using your script I was able to correctly save the output data, run the simulation using the C++ code, and then reload the output data. Could you say a few more words about your setup so we can try and replicate the error?</p> <p>Brad. </p> http://www.k-wave.org/forum/topic/data-loading-failed#post-6002 Tue, 20 Jun 2017 08:58:40 +0000 gaoyang.cai 6002@http://www.k-wave.org/forum/ <p>Hi Brad,</p> <p>Here is my complete script:</p> <pre><code>clear all; filename = &#39;temp.h5&#39;; alpha_coeff_input = 0.25; alpha_power = 1.75; % simulation settings data_cast = &#39;single&#39;; run_simulation = true; % ========================================================================= % DEFINE THE K-WAVE GRID % ========================================================================= % set the size of the perfectly matched layer (PML) PML_X_SIZE = 20; % [grid points] PML_Y_SIZE = 10; % [grid points] PML_Z_SIZE = 10; % [grid points] % set total number of grid points not including the PML mul = 2; Nx = mul*256 - 2*PML_X_SIZE; % [grid points] Ny = 256 - 2*PML_Y_SIZE; % [grid points] Nz = 64 - 2*PML_Z_SIZE; % [grid points] % set desired grid size in the x-direction not including the PML x = 45e-3; % [m] % calculate the spacing between the grid points dx = x/Nx; % [m] dy = mul*dx; % [m] dz = mul*dx; % [m] % create the k-space grid kgrid = makeGrid(Nx, dx, Ny, dy, Nz, dz); % ========================================================================= % DEFINE THE MEDIUM PARAMETERS % ========================================================================= % define the properties of the propagation medium c0 = 1540; % [m/s] rho0 = 1000; % [kg/m^3] % create the time array t_end = (Nx*dx)*2.2/c0; % [s] kgrid.t_array = makeTime(kgrid, c0, [], t_end); % ========================================================================= % DEFINE THE INPUT SIGNAL % ========================================================================= % % define properties of the input signal source_strength = 1e6; % [Pa] tone_burst_freq = 3e6; % [Hz] tone_burst_cycles = 4; % create the input signal using toneBurst input_signal = toneBurst(1/kgrid.dt, tone_burst_freq, tone_burst_cycles); % scale the source magnitude by the source_strength divided by the % impedance (the source is assigned to the particle velocity) input_signal = (source_strength./(c0*rho0)).*input_signal; % plot(input_signal); return, % ========================================================================= % DEFINE THE ULTRASOUND TRANSDUCER % ========================================================================= % physical properties of the transducer transducer.number_elements = 192; % total number of transducer elements transducer.element_width = 1; % width of each element [grid points] transducer.element_length = 24; % length of each element [grid points] transducer.element_spacing = 0; % spacing (kerf width) between the elements [grid points] transducer.radius = inf; % radius of curvature of the transducer [m] % calculate the width of the transducer in grid points transducer_width = transducer.number_elements*transducer.element_width ... + (transducer.number_elements - 1)*transducer.element_spacing; % use this to position the transducer in the middle of the computational grid transducer.position = round([1, Ny/2 - transducer_width/2, Nz/2 - transducer.element_length/2]); % properties used to derive the beamforming delays transducer.sound_speed = c0; % sound speed [m/s] transducer.focus_distance = 10000e-3; % focus distance [m] transducer.elevation_focus_distance = 30e-3;% focus distance in the elevation plane [m] transducer.steering_angle = 0; % steering angle [degrees] % apodization transducer.transmit_apodization = &#39;Rectangular&#39;; transducer.receive_apodization = &#39;Rectangular&#39;; % define the transducer elements that are currently active number_active_elements = 192; transducer.active_elements = ones(transducer.number_elements, 1); % append input signal used to drive the transducer transducer.input_signal = input_signal; % create the transducer using the defined settings transducer = makeTransducer(kgrid, transducer); % print out transducer properties transducer.properties; % ========================================================================= % DEFINE THE MEDIUM PROPERTIES % ========================================================================= % define a large image size to move across number_scan_lines = 1; Nx_tot = Nx; Ny_tot = Ny + number_scan_lines*transducer.element_width; Nz_tot = Nz; % define a random distribution of scatterers for the medium background_map_mean = 1; background_map_std = 0.008; background_map = background_map_mean + background_map_std*randn([Nx_tot, Ny_tot, Nz_tot]); % define a random distribution of scatterers for the highly scattering % region scattering_map = randn([Nx_tot, Ny_tot, Nz_tot]); scattering_c0 = c0 + 25 + 75*scattering_map; scattering_c0(scattering_c0 &gt; 1600) = 1600; scattering_c0(scattering_c0 &lt; 1400) = 1400; scattering_rho0 = scattering_c0/1.5; % define properties sound_speed_map = c0*ones(Nx_tot, Ny_tot, Nz_tot).*background_map; density_map = rho0*ones(Nx_tot, Ny_tot, Nz_tot).*background_map; % define a sphere for a highly scattering region radius = 7e-3; % [m] scattering_region3 = makeBall(Nx_tot, Ny_tot, Nz_tot, 3*Nx_tot/4, Ny_tot/2, Nz_tot/2, round(radius/dy)); scattering_region3 = repmat(scattering_region3(:,:,end/2),[1 1 Nz_tot]); % assign region sound_speed_map(scattering_region3 == 1) = scattering_c0(scattering_region3 == 1); density_map(scattering_region3 == 1) = scattering_rho0(scattering_region3 == 1); % ========================================================================= % SET HETEREGENEOUS ATTENUATION IN THE INCLUSION % ========================================================================= alpha_coeff = alpha_coeff_input ; medium.alpha_power = alpha_power ; medium.BonA = 5; % coefficient de non-linearit? % ========================================================================= % RUN THE SIMULATION % ========================================================================= % set the input settings input_args = {... &#39;PMLInside&#39;, false, &#39;PlotSim&#39;, false, &#39;PMLSize&#39;, [PML_X_SIZE, PML_Y_SIZE, PML_Z_SIZE], ... &#39;DataCast&#39;, data_cast}; % run the simulation if set to true, otherwise, load previous results from % disk % set medium position medium_position = 1; % load the current section of the medium medium.sound_speed = sound_speed_map(:, medium_position:medium_position + Ny - 1, :); medium.density = density_map(:, medium_position:medium_position + Ny - 1, :); medium.alpha_coeff = alpha_coeff; % run the simulation kspaceFirstOrder3D(kgrid, medium, transducer, transducer, input_args{:}, &#39;SaveToDisk&#39;, filename); save(filename(1:end-3));</code></pre> <p>Best<br /> Gaoyang </p> http://www.k-wave.org/forum/topic/data-loading-failed#post-6000 Mon, 19 Jun 2017 21:02:47 +0000 Bradley Treeby 6000@http://www.k-wave.org/forum/ <p>Hi Gaoyang,</p> <p>Could you post your complete script?</p> <p>Brad. </p> http://www.k-wave.org/forum/topic/data-loading-failed#post-5986 Thu, 15 Jun 2017 09:14:26 +0000 gaoyang.cai 5986@http://www.k-wave.org/forum/ <p>Hi!</p> <p>When I was try to execute C++ code, I got this message:</p> <p>Data loading ................. Failed!<br /> k-wave panic: Data loading was not successful!<br /> Error: could not read from "c0" dataset!</p> <p>But in my Matlab script, I have a parameter named c0 and set to 1540, so I can't understand why.<br /> Anyone please help me?</p> <p>Thanks!<br /> Gaoyang </p>