k-Wave User Forum » Topic: "Arrays have incompatible sizes for this operation."

k-Wave User Forum » Topic: "Arrays have incompatible sizes for this operation." http://www.k-wave.org/forum/topic/arrays-have-incompatible-sizes-for-this-operation Support for the k-Wave MATLAB toolbox en-US Tue, 12 May 2026 22:34:15 +0000 http://bbpress.org/?v=1.0.2 <![CDATA[Search]]> q http://www.k-wave.org/forum/search.php Bradley Treeby on ""Arrays have incompatible sizes for this operation."" http://www.k-wave.org/forum/topic/arrays-have-incompatible-sizes-for-this-operation#post-8930 Sun, 08 Oct 2023 13:09:26 +0000 Bradley Treeby 8930@http://www.k-wave.org/forum/ One cause of this problem is collision between the k-Wave smooth function, and the smooth function in the curve fitting toolbox. If you have this installed, try removing it from the MATLAB path, or alternatively, rename the k-Wave smooth function (eg to ksmooth). Sienna on ""Arrays have incompatible sizes for this operation."" http://www.k-wave.org/forum/topic/arrays-have-incompatible-sizes-for-this-operation#post-8845 Thu, 22 Jun 2023 10:43:33 +0000 Sienna 8845@http://www.k-wave.org/forum/ Hi, I've got the same problem. Working in version 1.4.0. Full error: Arrays have incompatible sizes for this operation. Error in kspaceFirstOrder2D (line 920) ux_sgx = dt .* rho0_sgx_inv .* real(ifft2( bsxfun(@times, ddx_k_shift_pos, kappa .* fft2(p)) )) / 2; Error in trial1 (line 30) sensor_data = kspaceFirstOrder2D(kgrid, medium, source, sensor); I had a look and I think the problem is within the multiplication of kappa (which is 128x128 double) and fft2(p) (which is 16384x1). But I do not know how to solve it. Any help is appreciated! Thankyou. --- Update: I solved it for now, for others: Smooth changed the source.p0 from 128x128 to 16384x1, so you can circumvent by running the simulation by: sensor_data = kspaceFirstOrder2D(kgrid, medium, source, sensor, Smooth=[false,false,false]); Bradley Treeby on ""Arrays have incompatible sizes for this operation."" http://www.k-wave.org/forum/topic/arrays-have-incompatible-sizes-for-this-operation#post-8760 Thu, 18 May 2023 06:16:58 +0000 Bradley Treeby 8760@http://www.k-wave.org/forum/ The first one is old syntax, but your second example I'm able to run without any errors in k-Wave 1.4. Could you post the full error message? Have you tried selecting "Run the file in MATLAB" for any of the examples in the MATLAB help browser? sjm212 on ""Arrays have incompatible sizes for this operation."" http://www.k-wave.org/forum/topic/arrays-have-incompatible-sizes-for-this-operation#post-8751 Sun, 14 May 2023 19:00:22 +0000 sjm212 8751@http://www.k-wave.org/forum/ Hi All, I am just starting out with the k-wave toolbox and have begun working through the examples to get a grasp on the functionality. I immediately ran into issues when running the kspaceFirstOrder2D function getting the "Arrays have incompatible sizes for this operation." error multiple times from multiple examples. Listed below are the scripts I have run to get the errors. %% ----- %% From the User Manual: % create the computational grid Nx = 128; % number of grid points in the x (row) direction Ny = 256; % number of grid points in the y (column) direction dx = 50e-6; % grid point spacing in the x direction [m] dy = 50e-6; % grid point spacing in the y direction [m] kgrid = makeGrid(Nx, dx, Ny, dy); % define the medium properties medium.sound_speed = 1500*ones(Nx, Ny); % [m/s] medium.sound_speed(1:50, :) = 1800; % [m/s] medium.density = 1040; % [kg/m^3] % define an initial pressure using makeDisc disc_x_pos = 75; % [grid points] disc_y_pos = 120; % [grid points] disc_radius = 8; % [grid points] disc_mag = 3; % [Pa] source.p0 = disc_mag*makeDisc(Nx, Ny, disc_x_pos, disc_y_pos, disc_radius); % define a Cartesian sensor mask of a centered circle with 50 sensor elements sensor_radius = 2.5e-3; % [m] num_sensor_points = 50; sensor.mask = makeCartCircle(sensor_radius, num_sensor_points); % run the simulation sensor_data = kspaceFirstOrder2D(kgrid, medium, source, sensor); From the MATLAB Examples Site: % 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); % 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; % create initial pressure distribution using makeDisc disc_magnitude = 5; % [Pa] disc_x_pos = 50; % [grid points] disc_y_pos = 50; % [grid points] disc_radius = 8; % [grid points] disc_1 = disc_magnitude * makeDisc(Nx, Ny, disc_x_pos, disc_y_pos, disc_radius); disc_magnitude = 3; % [Pa] disc_x_pos = 80; % [grid points] disc_y_pos = 60; % [grid points] disc_radius = 5; % [grid points] disc_2 = disc_magnitude * makeDisc(Nx, Ny, disc_x_pos, disc_y_pos, disc_radius); source.p0 = disc_1 + disc_2; % define a centered circular sensor sensor_radius = 4e-3; % [m] num_sensor_points = 50; sensor.mask = makeCartCircle(sensor_radius, num_sensor_points); % run the simulation sensor_data = kspaceFirstOrder2D(kgrid, medium, source, sensor); %% ----- %% What is interesting is that running Program 1 from page 3 of Treeby et al. (<a href="http://bug.medphys.ucl.ac.uk/papers/2014-Treeby-IEEEIUS.pdf" rel="nofollow">http://bug.medphys.ucl.ac.uk/papers/2014-Treeby-IEEEIUS.pdf</a>) leads to no errors and a properly run simulation. Any help would be greatly appreciated! Sincere Thanks, SJM212