k-Wave User Forum » Topic: change frequency of toneBurst

k-Wave User Forum » Topic: change frequency of toneBurst http://www.k-wave.org/forum/topic/change-frequency-of-toneburst Support for the k-Wave MATLAB toolbox en-US Tue, 12 May 2026 22:27:04 +0000 http://bbpress.org/?v=1.0.2 <![CDATA[Search]]> q http://www.k-wave.org/forum/search.php Bradley Treeby on "change frequency of toneBurst" http://www.k-wave.org/forum/topic/change-frequency-of-toneburst#post-6785 Sun, 17 Mar 2019 22:43:11 +0000 Bradley Treeby 6785@http://www.k-wave.org/forum/ Hi Haixiao, You should define your sampling frequency to be the same sampling frequency used by the simulation, i.e., <code>1/kgrid.dt</code>. This will mean defining the time sampling before you define your source signal, e.g., by calling the <code>makeTime</code> or <code>setTime</code> methods of the <code>kWaveGrid</code> class. Brad. haixiao on "change frequency of toneBurst" http://www.k-wave.org/forum/topic/change-frequency-of-toneburst#post-6764 Fri, 01 Mar 2019 04:46:29 +0000 haixiao 6764@http://www.k-wave.org/forum/ Hello,Tristan Thank you for your answer! So in order to observe the difference between waves at different frequencies, how should I set the sampling and signal frequencies. I'm always a little confused about their relation. Thank you in advance! Best regards, Haixiao Tristan2 on "change frequency of toneBurst" http://www.k-wave.org/forum/topic/change-frequency-of-toneburst#post-6763 Thu, 28 Feb 2019 12:28:14 +0000 Tristan2 6763@http://www.k-wave.org/forum/ Hi Haixiao, why do you expect it to be any different? The signal (in terms of samples) should look exactly the same if you scale the sampling and signal frequencies by the same amount. If you look at it in terms of time, the signal with the higher frequency is 10000 times shorter. Best regards, Tristan haixiao on "change frequency of toneBurst" http://www.k-wave.org/forum/topic/change-frequency-of-toneburst#post-6762 Thu, 28 Feb 2019 04:45:34 +0000 haixiao 6762@http://www.k-wave.org/forum/ hi, my name is haixiao. I've been getting a lot of help from this tool to study acoustics. But I am also quiet new to this tool and matlab. I really appreciate if you could provide help. I'd like to use toneBurst to generate waves with different frequencies. But when I make some changes, for example, if I change the 'tone_burst_freq' from 500 Hz to 5,000,000 Hz and the 'sampling_freq' from 10,000 Hz to 100,000,000 Hz, to see the difference between 500 Hz wave and 5 MHz wave, the results are the same. But it should be different. I'm not sure what kind of problems I have made. Thank you for your help! here is the code I used and please feel free to run it to see what I am talking about. again, I would greatly appreciate any help you could give. --------------------------------------------------------------------------------------- clear all; % define the grids Nx = 300; Ny = 300; dx = 75e-3; % m dy = 75e-3; % m kgrid = kWaveGrid(Nx,dx,Ny,dy); % create the grid % define the medium terms medium.sound_speed = 1500*ones(Nx,Ny); % m * s^(-1) water medium.density = 997; % kg * m^(-3) water % define the source.p mask disc5 = zeros(Nx,Ny); circle = makeCircle(300,300,150,150,100,(90/180)*pi); disc5 = disc5+circle; source.p_mask = disc5; % define a tone burst sampling_freq = 1e4; % Hz 10000 or 100,000,000 tone_burst_freq = 5e2; % Hz 500 or 5,000,000 tone_burst_cycles = 1; source.p = 2*toneBurst(sampling_freq, tone_burst_freq, tone_burst_cycles); % define the sensor terms sensor.mask = eye(Nx,Ny);%diag(r,0); % run the simulation sensor_data = kspaceFirstOrder2D(kgrid,medium,source,sensor); % draw the figure figure; imagesc(sensor_data, [-1, 1]); colormap(getColorMap); ylabel('Sensor Position'); xlabel('Time Step'); colorbar;