RZV
This routine is used to ratio zone the region of space spanned by the input number ni of copies of the input vector vij away from the initial point v0j using the desired coordinate system. No attempt is made to insure that the 3 vectors are independent.
For ratio_method = component (default), the j-th component of the i-th vector vij is reduced by  rij  after the ki -th
step in the i-th direction away from the initial point.  For this ratio_method the ratio flags fi are not used.  In this case an initial step of 1 for the j-th component of the i-th direction would become, for rij  =  1/2, a step of the j-th component of the i-th direction of 1/2 at ki =  1, 1/4 at  ki =  2, 1/8 at  ki =  3, 1/16 at ki =  4,etc.
For ratio_method = vector and fj =1 (the default), the j-th vecor is reduced by rij  after the ki -th step in the i-th direction.  In this case an initial step of 1 in the j-th direction would become, for  rij  =  1/2, a setp in the j-th direction of 1/2 at ki =  1, 1/4 at  ki =  2, 1/8 at  ki =  3, 1/16 at ki =  4,etc.
For ratio_method = vector and fj =0, the j-th vecor is reduced by [1 - (1-rij  )*2/(ki +  1)] after the ki -th step in the i-th direction.  In this case an initial step of 1 in the j-th direction would become, for  rij  =  1/2, a step in the j-th direction of 1/2 at ki =  1, 1/3 at  ki =  2, 1/4 at  ki =  3, 1/5 at ki =  4,etc.
FORMAT:
rzv/xyz|rtz|rtp /
[ n1,n2,n3
/v11,v12,v13/v21,v22,v23/v31,v32,v33
/v01,v02,v03
/r11,r12,r13/r21,r22,r23/r31,r32,r33
/component|vector
/f1,f2,f3]
default = xyz
default = 0:      ni, vi, v0j
default = 1:      rij
default = component
EXAMPLES: spiral of points rzv/rtz/n1,0,0/.1,10.,1/ , , / , , / , , /1.1,1,.9/ sc (simple cubic) point distribution rzv/xyz/n1,n2,n3/1,0,0/0,1,0/0,0,1/         same as
rz/xyz/n1+1,n2+1,n3+1/0,0,0/n1,n2,n3/1,1,1
bcc (body centered cubic) point distribution rzv/xyz/n1,n2,n3/.5,.5,.5/.5,.5,-.5/.5,-.5,-.5/
compare the two command sequence (different bounding box) rz/xyz/n1+1,n2+1,n3+1/0,0,0/n1,n2,n3/1,1,1
rz/xyz/n1  ,n2  ,n3  /0,0,0/n1,n2,n3/0,0,0
fcc (face centered cubic) point distribution rzv/xyz/n1,n2,n3/.5,.5,0/0,.5,.5/.5,0,.5/
compare the four command sequence (different bounding box) rz/xyz/n1+1,n2+1,n3+1/0,0,0/n1,n2,n3/1,1,1
rz/xyz/n1  ,n2  ,n3+1/0,0,0/n1,n2,n3/0,0,1
rz/xyz/n1  ,n2+1,n3  /0,0,0/n1,n2,n3/0,1,0
rz/xyz/n1+1,n2  ,n3  /0,0,0/n1,n2,n3/1,0,0
hexagonal lattice of points in x,y plane, repeated in z direction rzv/xyz/n1,n2,n3/1,0,0/.5,0.866,0/0,0,1/ diamond point distribution (two command sequence) rzv/xyz/n1,n2,n3/.5,.5,0/0,.5,.5/.5,0,.5/           rzv/xyz/n1,n2,n3/.5,.5,0/0,.5,.5/.5,0,.5/.25,.25,.25 compare the eight command sequence (different bounding box) rz/xyz/n1+1,n2+1,n3+1/0,0,0/n1,n2,n3/1,1,1           rz/xyz/n1  ,n2  ,n3+1/0,0,0/n1,n2,n3/0,0,1
rz/xyz/n1  ,n2+1,n3  /0,0,0/n1,n2,n3/0,1,0
rz/xyz/n1+1,n2  ,n3  /0,0,0/n1,n2,n3/1,0,0 rz/xyz/n1+1,n2+1,n3+1/0.25,0.25,0.25/n1+.25,n2+.25,n3+.25/1,1,1
rz/xyz/n1  ,n2  ,n3+1/0.25,0.25,0.25/n1+.25,n2+.25,n3+.25/0,0,1
rz/xyz/n1  ,n2+1,n3  /0.25,0.25,0.25/n1+.25,n2+.25,n3+.25/0,1,0
rz/xyz/n1+1,n2  ,n3  /0.25,0.25,0.25/n1+.25,n2+.25,n3+.25/1,0,0
hcp (hexagonal close pack) point distribution  (two command sequence) rzv/xyz/n1,n2,n3/1,0,0/.5,0.866,0/0,0,1/
rzv/xyz/n1,n2,n3/1,0,0/.5,0.866,0/0,0,1/.5,0.289,.5/
nice 2-d distribution of points in a circle of radius 1 rzv/xyz/10,60,0/0.1,0,0/0,60,0/0,0,1/0,0,0/1,0.5,1/1,1,1/1,1,1/vector/0,0,0

CAVEATS -
* filter should be used afterwards to remove possibly duplicate points
* this can create some really bizzare point distributions
* mistyped input after "rzv/[cgeom]" always returns successful point addition,
but may be very different than desired
* ratio_flag might better be a scalar or a matix, and its use might want to be extended to ratio_method=component.