y = numpy.log10(numpy.arange(1, 101)) * 20
In [30]: numpy.arange(1, 10)
Out[30]: array([1, 2, 3, 4, 5, 6, 7, 8, 9])
In [31]: numpy.log10(numpy.arange(1, 10))
Out[31]:
array([ 0. , 0.30103 , 0.47712125, 0.60205999, 0.69897 ,
0.77815125, 0.84509804, 0.90308999, 0.95424251])
In [32]: numpy.log10(numpy.arange(1, 10)) * 20
Out[32]:
array([ 0. , 6.02059991, 9.54242509, 12.04119983,
13.97940009, 15.56302501, 16.9019608 , 18.06179974, 19.08485019])