Python
import matplotlib.pyplot as pl
import numpy as no
data=[5,25,45,20],[8,13,29,27],[9,29,27,39]
x=[1,2,3,4]
pl.bar(x,data[0])
pl.bar(x+0.24,data[1])
pl.bar(x+0.50,data[2])
pl.show
line 6, in <module>
    pl.bar(x+0.24,data[1])
           ~^~~~~
TypeError: can only concatenate list (not "float") to list