This command sets the marker typ to be used for the found maxima of data set <ik>. The allowed values for <p> are:
0 : no marker 4 : empty square 8 : cross (+) 1 : dot 5 : filled square 9 : vertical line 2 : empty circle 6 : empty triangle 10 : vertical line from 3 : filled circle 7 : cross (x) x-axis