x

x coordinate

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Discussion

The values Lx and Nx are set during initialization from which the x coordinate is derived.

The x coordinate is periodic, which means that

dx = Lx/Nx;
x = dx*(0:Nx-1)';

Note that this means that it is NOT true that Lx=x(end)-x(1), but in fact you need an extra grid point, i.e., it IS true that Lx = dx + x(end)-x(1). This is the usual grid for Fourier Transforms.