jsele <is>, "all" |<name>|<number>, [ ... ]
This command selects atom types given either by <name> or <number>
for the PDF calculation. All other atoms are ignored. This allows
the calculation of differential or partial PDFs. The two commands
allow one to select atom types for each atom in a pair 'ij'
contributing to the PDF calculation. The first parameters <is>
specifies the number of the corresponding data set.