Access properties with .nameand .name = value.

dir : 1/-1
Gives the direction of the base with respect to the helical axis (the +z direction of the lattice). If dir is +1, then the base is on the strand which is aligned with the +z direction (the 3' end is towards the positive side). If dir is -1, the base is on the strand which is anti-aligned (the 5' end is towards the positive side):
```
------------------> +z
5'-b-3'    3'-b-5'
  +1         -1
```
pos : Array
4-component array giving the position of this base. The 4 components should be: [x, y, z1, z2], where x and y give the helix position, z1 gives the position of the domain/voxel along the helix, and z2 gives the position of the base within the domain. z2 may be given as -1 as well, in order to specify that the base is off the lattice.
seq : String
Gives the sequence of this base, if known. When sequences are generated, this base will be treated as locked if a base is given here. If this property is falsy, then the sequence will be assigned by the sequence set.

Base vox.dna.Base