TEXT(Helical-pipe grid, made by DO loop :B102
TITLE
  originated by dbs April '93
nx=8;ny=6;nz=12
bfc=t
 
mesg(create helical grid? y/n
readvdu(ans,char,y)
if(:ans:.eq.y) then
 mesg(this q1 creates a helical grid by means of a DO loop
 real(xx,yy,zz,zfac,snxx,csxx,littler,bigr)
 real(twopi,xxc,yyc,zzc,yyy,cszz,snzz)
 littler=0.2;bigr=1.0;twopi=2.0*3.14157
 gset(d,nx,ny,nz)
 nx
 ny
 nz
 
 do ii=1,nx+1
 ii
 xx=twopi*(ii-1)/nx
 snxx=sin(xx)
 csxx=cos(xx)
 do jj=1,ny+1
 yy=littler*(jj-1)/ny
 xxc=yy*csxx
 yyy=yy*snxx
 
 do kk=1,nz+1
 zfac=(kk-1)/nz
 zz=twopi*zfac
 cszz=cos(zz)
 snzz=sin(zz)
 yyc=(bigr+yyy)*cszz
 zzc=(bigr+yyy)*snzz
 xc(ii,jj,kk)=xxc+zfac*2.0*littler
 yc(ii,jj,kk)=yyc
 zc(ii,jj,kk)=zzc
 
 enddo
 enddo
 enddo
else
 
 mesg(read a grid file? y/n
 readvdu(ans,char,n)
 if(:ans:.eq.y) then
+ nx=12;ny=6;nz=24
+ readco(xyz)
 endif
 
endif
view(j,ny+1)
gview(p,1,1,1);gdraw