k-Wave User Forum » Topic: Error using expandMatrix when executing kspaceFirstOrder3D function

k-Wave User Forum » Topic: Error using expandMatrix when executing kspaceFirstOrder3D function http://www.k-wave.org/forum/topic/error-using-expandmatrix-when-executing-kspacefirstorder3d-function Support for the k-Wave MATLAB toolbox en-US Thu, 14 May 2026 01:37:51 +0000 http://bbpress.org/?v=1.0.2 <![CDATA[Search]]> q http://www.k-wave.org/forum/search.php songhw91 on "Error using expandMatrix when executing kspaceFirstOrder3D function" http://www.k-wave.org/forum/topic/error-using-expandmatrix-when-executing-kspacefirstorder3d-function#post-9149 Sun, 06 Oct 2024 22:40:24 +0000 songhw91 9149@http://www.k-wave.org/forum/ Hi, I've defined a 3d grid and trying to run the kspaceFirstOrder3D function. However, the error message shows "Error using expandMatrix exp_coeff must be a 1 or 2 element array. Error in kspaceFirstOrder_expandGridMatrices (line 160) source.p0 = expandMatrix(source.p0, expand_size, 0); Error in kspaceFirstOrder_inputChecking (line 1558) kspaceFirstOrder_expandGridMatrices; Error in kspaceFirstOrder3D (line 574) kspaceFirstOrder_inputChecking; Error in kWave_PSI_simulation (line 102) sensorDataTmp = kspaceFirstOrder3D(kgrid, medium, source, sensor, input_args{:});" I've checked the example script as well, but same issue is happening. It seems that this is something related to built in functions.. I appreciate any solutions. Here is my script for your reference. clc; clear; close all; %% c = 1540; fs = 30e6; % fc = 2e6; % band_width = 50; % percent % pass_band = nFc * (1+[-band_width band_width]/100) / nFs * 2; bRecord = false; % computation settings file_name = 'PSI_simulation'; input_args = {'DataCast', 'single',... 'PlotLayout',true,... 'PMLInside',false,... 'PlotPML',false,... 'RecordMovie', bRecord,... 'MovieName', file_name,... 'MovieProfile', 'MPEG-4'}; %% dir_cur = pwd; dirSave = [dir_cur '/../data/Acoustic_simulation/' file_name]; mkdir(dirSave); %% dimension & phantom setup % size of the computational grid grid_size = 2*[40 40 10]*1e-3; % x, y, z grid_interval = [1 1 1]*5e-4; Nx = round(grid_size(1)/grid_interval(1)); Ny = round(grid_size(2)/grid_interval(2)); Nz = round(grid_size(3)/grid_interval(3)); kgrid = kWaveGrid(Nx, grid_interval(1), Ny, grid_interval(2), Nz, grid_interval(3)); axis_x = linspace(-0.5*(Nx-1), 0.5*(Nx-1), Nx)*grid_interval(1); axis_y = linspace(-0.5*(Ny-1), 0.5*(Ny-1), Ny)*grid_interval(2); axis_z = linspace(0, Nz-1, Nz)*grid_interval(3); %% scanning sequence scanning_interval = [1 1]*1e-3; % x, y scanning_pos_x = -0.5*(grid_size(1)/2):scanning_interval(1):0.5*(grid_size(1)/2); scanning_pos_y = -0.5*(grid_size(2)/2):scanning_interval(2):0.5*(grid_size(2)/2); [scanning_pos_y, scanning_pos_x] = ndgrid(scanning_pos_x, scanning_pos_y); scanning_pos_y_grid = round((scanning_pos_y + grid_size(2)/2)/grid_interval(2))+1; scanning_pos_x_grid = round((scanning_pos_x + grid_size(1)/2)/grid_interval(1))+1; %% target target_pos = [0 0 1; 0 10 1; 10 0 1; 10 10 1; 0 -10 1; -10 0 1; -10 -10 1; -10 10 1; 10 -10 1; % 0 0 2; 0 1 2; 1 0 2; 1 1 2; 0 -1 2; -1 0 2; -1 -1 2; -1 1 2; 1 -1 2; 0 0 3; 0 10 3; 10 0 3; 10 10 3; 0 -10 3; -10 0 3; -10 -10 3; -10 10 3; 10 -10 3; % 0 0 4; 0 1 4; 1 0 4; 1 1 4; 0 -1 4; -1 0 4; -1 -1 4; -1 1 4; 1 -1 4; 0 0 5; 0 10 5; 10 0 5; 10 10 5; 0 -10 5; -10 0 5; -10 -10 5; -10 10 5; 10 -10 5; % 0 0 6; 0 1 6; 1 0 6; 1 1 6; 0 -1 6; -1 0 6; -1 -1 6; -1 1 6; 1 -1 6; 0 0 7; 0 10 7; 10 0 7; 10 10 7; 0 -10 7; -10 0 7; -10 -10 7; -10 10 7; 10 -10 7; % 0 0 8; 0 1 8; 1 0 8; 1 1 8; 0 -1 8; -1 0 8; -1 -1 8; -1 1 8; 1 -1 8; 0 0 9; 0 10 9; 10 0 9; 10 10 9; 0 -10 9; -10 0 9; -10 -10 9; -10 10 9; 10 -10 9;]'*1e-3; voxel_targets = cart2grid(kgrid, target_pos); %% source and sensor source_diameter = 1e-3; source_mag = 100; sensor_diameter = 1e-3; sensor_map = zeros(Nx,Ny); for k = 1:numel(scanning_pos_x_grid) disc_tmp = makeDisc(Nx, Ny, scanning_pos_x_grid(k), scanning_pos_y_grid(k), round(0.5*sensor_diameter/grid_interval(1))); sensor_map = sensor_map|disc_tmp; end sensor_mask = zeros(Nx, Ny, Nz); sensor_mask(:,:, Nz/2) = sensor_map; sensor.mask = sensor_mask; %% medium.sound_speed = c * ones(Nx, Ny, Nz); % [m/s] medium.sound_speed(voxel_targets==1) = 1600; % [m/s] speed of sound in hard target medium.sound_speed(:,:,Nz/2:end) = 340; % [m/s] speed of sound in air medium.density = 1000 * ones(Nx, Nx, Nz); % [kg/m^3] Soft tissue density medium.density(voxel_targets==1) = 1200; % [kg/m^3] tissue density of blood medium.density(:,:,Nz/2:end) = 1.3; % [kg/m^3] density of air %% % for k = 1:numel(scanning_pos_y) for k = 1 % make source ball_tmp = makeBall(Nx, Ny, Nz, scanning_pos_x_grid(k), scanning_pos_y_grid(k), Nz/2, round(0.5*source_diameter/grid_interval(1))); ball_tmp(:,:,1:Nz/2-1) = 0; source.p0 = source_mag * ball_tmp; % run the simulation sensorDataTmp = kspaceFirstOrder3D(kgrid, medium, source, sensor, input_args{:}); end