Unpack Java jars
Apparently java files are archives! Laut Extracting the Contents of a JAR File (The Java™ Tutorials > Deployment > Packaging Programs in JAR Files) it’s
jar xf jar-file [archived-file(s) to extract].
Pandas and numpy have different std/stdev standard deviation functions!
Both are correct, one divides by N, the other by N-1.
t df.std()==np.std(df, ddof=1). Somethingsomething delta degrees of freedom.
ddof=0 can also be passed to pandas.