NMSE example 3.10
pf,          0
pd,       7081
test,         time,            max,            avg
if,         721251,              0,           -nan
id,    2.30016e+06,             63,        44.8311
of,    1.48641e+06,              0,           -nan
od,    5.91991e+06,        61.9986,        5.31066
df,              0,              0
dd,        61.9975,            519