section t of routines in hex.i

functions in hex.i - t

track_combine


    nlist = track_combine(nm,cm,sm, np,cp,sp, c, s)  


combine two track_reduce results NM,CM,SM, and NP,CP,SP,  
which represent the first and second halves of a set of  
rays.  See bi_dir for a typical application.  The returned  
NLIST is NM+NP, or NM+NP-1 for those rays where the  
final CM is identical to the initial CP.  
C, S, together with NLIST are the output arrays, as for  
track_reduce.  
Interpreted function, defined at i0/hex.i   line 270

SEE ALSO: track_reduce, bi_dir

track_integ


    result= track_integ(nlist, transp, selfem, last)  


integrates a transport equation by doing the sums:  
   transparency(i) = transparency(i-1) * TRANSP(i)  
   emissivity(i) = emissivity(i-1) * TRANSP(i) + SELFEM(i)  
returning only the final values transparency(n) and emissivity(n).  
The NLIST is a list of n values, so that many transport integrals  
can be performed simultaneously; sum(NLIST) = numberof(TRANSP) =  
numberof(SELFEM).  The result is 2-by-dimsof(NLIST).  
If TRANSP is nil, result is dimsof(NLIST) sums of SELFEM.  
If SELFEM is nil, result is dimsof(NLIST) products of TRANSP.  
TRANSP and SELFEM may by 2D to do multigroup integrations  
simultaneously.  By default, the group dimension is first, but  
if LAST is non-nil and non-zero, the group dimension is second.  
In either case, the result will be ngroup-by-2-by-dimsof(NLIST).  
track_solve is the higher-level interface.  
Interpreted function, defined at i0/hex.i   line 397

SEE ALSO: track_reduce, track_solve, track_solve

track_reduce


    nlist= track_reduce(c, s)  
 or nlist= track_reduce(c, s, rays, slimits)  


compresses the C and S returns from the tracking routines (see  
hex5_track) to the following form:  
  [cell1,cell2,cell3,..., cell1,cell2,cell3,..., ...]  
  [s1-s0,s2-s1,s3-s2,..., s1-s0,s2-s1,s3-s2,..., ...]  
returning nlist as  
  [#hits, #hits, ...]  
In this form, any negative #hits are combined with the preceding  
positive values, and #hits=1 (indicating a miss) appear as #hits=0  
in nlist.  Hence, nlist always has exactly Nrays elements.  
If RAYS is supplied, it is used to force the dimensions of the  
returned nlist to match the dimensions of RAYS (the value of RAYS  
is never used).  The RAYS argument need not have the trailing 2  
dimension, so if you specified RAYS as [P,Q] if the call to  
hex5_track, you can use just P or Q as the RAYS argument to  
track_reduce.  
If SLIMITS is supplied, it should be [smin,smax] or [smin,smax]-  
by-dimsof(nlist) in order to reject input S values outside the  
specified limits.  The C list will be culled appropriately, and  
the first and last returned ds values adjusted.  
With a non-zero flip= keyword, the order of the elements of  
C and S within each group of #hits is reversed, so that a  
subsequent track_solve will track the ray backwards.  If you  
use this, both the ray direction input to the tracking routine  
and any SLIMITS argument here should refer to the reverse of  
the ray you intend to track.  
Interpreted function, defined at i0/hex.i   line 158

SEE ALSO: hex5_track, c_adjust, track_solve, track_integ, bi_dir,
track_combine

track_solve


    result= track_solve(nlist, c, s, akap, ekap, last)  


integrates a transport equation for NLIST, C, and S returned  
by track_reduce (and optionally c_adjust).  The RAYS argument  
is used only to set the dimensions of the result.  AKAP and  
EKAP are mesh-sized arrays of opacity and emissivity, respectively.  
They may have an additional group dimension, as well.  The  
units of AKAP are 1/length (where length is the unit of S),  
while EKAP is (spectral) power per unit area (length^2), where  
the power is what ever units you want the result in.  The  
emission per unit volume of material is EKAP*AKAP; an optically  
thick block of material emits EKAP per unit surface.  
The NLIST is a list of n values, so that many transport integrals  
can be performed simultaneously; sum(NLIST) = numberof(AKAP) =  
numberof(EKAP).  The result is 2-by-dimsof(NLIST), where the  
first element of the first index is the transmission fraction  
through the entire ray path, and the second element of the  
result is the self-emission along the ray, which has the same  
units as EKAP.  
If EKAP is nil, result is dimsof(NLIST) -- exactly the same as  
the transparency (1st element of result) when both EKAP and AKAP  
are specified.  
If AKAP is nil, result is dimsof(NLIST).  In this case, EKAP  
must have units of emission per unit volume instead of per unit  
area; the result will be the sum of EKAP*S along each ray.  
AKAP and EKAP may by 2D to do multigroup integrations  
simultaneously.  By default, the group dimension is first, but  
if LAST is non-nil and non-zero, the group dimension is last.  
In either case, the result will be ngroup-by-2-by-dimsof(NLIST).  
To use in conjuction with hex5_track, one might do this:  
   c= hex5_track(mesh, rays, s);  
   nlist= track_reduce(c, s, rays);  
   c_adjust, c, mesh;  // if necessary  
   result= track_solve(nlist, c, s, akap, ekap);  
Interpreted function, defined at i0/hex.i   line 456