Hi there, It's the first time I am using gnuplot to plot a graph and I watched all sorts of tutorials and advices on google but I just can't find a good solution! Let me try to explain what the problem is... The experiment: I have a microphone and a speaker in closed box. The speaker is fixed in one corner but the microphone is movable on the x axis (along the edge of the box - inside, of course). I get a .dat file with three columns. The first column is frequency which is constant at 304 Hz, the second and third column are both voltage, second is voltage amplitude and third average voltage (one measure is 3 s long). I have to "walk" the entire box, so the x goes from 0 cm to 50 cm (steps by 1 cm). (all measurements are thereby discrete). Now how on earth can I convince gnuplot to plot me x axis with values from 0 to 50 and for y axis to call data from .dat file? I hope my english isn't too bad. Thanks for your help!