Ranges

GSL allows you to specify ranges of residue or atom numbers.

Specifying ranges

  • Using to:

    resid 14 to 20

    Selects atoms in residues numbered 14 through 20 (including 20).

  • Using -:

    resid 14-20

    Equivalent to resid 14 to 20.

Combining with multiple ranges and numbers

You can mix explicit numbers with ranges for more complex selections.

  • Example:

    serial 1 3 to 6 10 12-14 17

    Expands to selecting serial numbers 1, 3, 4, 5, 6, 10, 12, 13, 14, and 17.

Open-ended ranges

GSL supports open-ended ranges using comparison operators.

  • Operators:

    • < : Less than
    • > : Greater than
    • <=: Less than or equal to
    • >=: Greater than or equal to

  • Examples:

    serial <= 180

    Selects all atoms with serial numbers ≤ 180.

    resid > 33

    Selects atoms in residues numbered 34 and above.

Combining open-ended and explicit selections

  • Example:

    serial 1 3-6 >=20

    Selects atoms with serial numbers 1, 3, 4, 5, 6, and 20 or higher.