def shift_feature_to_x0(xdata, ydata, x0=<NUM_LIT:0>, feature=imax):
i = feature(ydata)<EOL>return xdata-xdata[i]+x0, ydata<EOL>
Finds a feature in the the ydata and shifts xdata so the feature is centered
at x0. Returns shifted xdata, ydata. Try me with plot.tweaks.manipulate_shown_data()!

xdata,ydata     data set
x0=0            where to shift the peak
feature=imax    function taking an array/list and returning the index of said feature