clear variables;

Nt=10240;

dt=1e-4;

Nx = 2048;

dx = 1e-1; %when I change dx from 1e-1 to 1e-2, an unexpected sound appears

kgrid = kWaveGrid(Nx, dx);

medium.sound_speed =340; %[m/s]

medium.density = 1.29; % [kg/m^3]

source.p0=zeros(Nx,1);

source.p_mask=zeros(Nx,1);

source.p_mask(2,1)=1; % Define the real Sound Source's position

m=zeros(Nx,1);

m(100,1)=1;

sensor.mask=m;

kgrid.setTime(Nt, dt);

source.p=100 * sin(2 * pi * 150 * kgrid.t_array);

sensor_data = kspaceFirstOrder1D(kgrid, medium, source, sensor);

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My codes are above, when I change dx from 1e-1 to 1e-2, at the end of x-axis there will be an unexpected sound source which send a sound wave to the real sound source. Is this a bug or I have something wrong??