Results of the Fourier analysis on artificial data obtained by simulating a slow propagating wave mode. The left histograms show the phase differences between perturbations in the LOS magnetic field, the LOS velocity, and the intensity. The right histograms show the phase speed ω/k, the sound speed c_s, and the vertical wave number k which have been calculated from the inverted amplitude ratios. The average of the histograms is indicated by the short vertical line and one standard deviation by the horizontal line. In the right histograms there is also a vertical line showing the value used in the simulation.