section d of routines in drat.i

functions in drat.i - d

default_gate


    default_gate(times)  


initial value of drat_gate.  Refer to the source code  
to learn how to write your own gate function, making proper use  
of drat_start and drat_stop options in addition to the input times.  
Interpreted function, defined at i0/drat.i   line 774

SEE ALSO: drat_glist, adjust_ireg

drat_backlight


    func drat_backlight(time) { extern gb, gav;  ... }  
 or drat_backlight=   
 or drat_backlight=   


supplies a backlighter for the snap function.  
Given ngroup-by-nrays transparency fraction transp and self-emission  
selfem (in specific intensity units), snap applies the backlighter  
using:  
   result= backlighter*transp + selfem;  
where backlighter is drat_backlight(time), if drat_backlight is  
a function, or drat_backlight itself, if drat_backlight is an  
array.  
Note that the result (or value) of backlighter_func must be  
conformable with transp and selfem.  Most commonly, drat_backlight  
will be a vector of length ngroup -- a Planckian backlighter at  
temperature Tr would be  
   drat_backlight= B_nu(gav, Tr);  
-- but that a scalar, 1-by-nrays, or ngroup-by-nrays are all  
possible.  
Note also that if drat_backlight is a function, the gb and gav  
arrays read from the history file are available as external  
variables.  
Keyword,  defined at i0/drat.i   line 586

SEE ALSO: snap, drat_channel, drat_gate, apply_funcs

drat_channel


    func drat_channel(time) { extern gb, gav;  ... }  
 or drat_channel=   
 or drat_channel=   


supplies a channel response for the snap function.  
Use the drat_glist option to select a subset of the groups;  
drat_channel can be used in addition to drat_glist.  
Given ngroup-by-nrays specific intensity, snap applies the  
channel response using:  
   result= drat_channel(..,+)*specific_intensity(+,..);  
if drat_channel is an array, or  
   result= drat_channel(specific_intensity, time);  
if drat_channel is a function.  
Note that if drat_channel is an array, its final dimension must  
be of length ngroup.  A multidimensional drat_channel represents  
more than one channel response function.  Most drat_channel  
arrays will be proportional to the bin widths gb(dif).  The  
correct way to interpolate a filter function transmission  
fraction known at photon enrgies efa is:  
   drat_channel= integ(ffa, efa, f.gb)(dif)  
If you have more than one channel, the first dimension of  
drat_channel should be the channel number.  
The best way to generate a filter response function is to  
use Yorick's cold opacity library.  To do this:  
   #include "coldopac/xray.i"  
This will define the functions cold_opacity and cold_reflect,  
which you can use to build up channel response functions from  
filter materials and thicknesses and mirror compositions.  
Note also that if drat_channel is a function, the gb and gav  
arrays read from the history file are available as external  
variables.  
Keyword,  defined at i0/drat.i   line 614

SEE ALSO: drat_glist, snap, drat_backlight, drat_gate, apply_funcs

drat_compress


    func drat_compress(transp, selfem, time)  
 or drat_compress=   


supplies a compression algorithm to the streak function.  
The drat_compress can return anything, as long as it returns the  
same shape array (or nil) at each time.  The snap_worker and  
streak_saver routines are examples of compression algorithms.  
Keyword,  defined at i0/drat.i   line 577

drat_ekap


    drat_ekap  


Keyword,  defined at i0/drat.i   line 447

SEE drat_rt

drat_emult


    drat_emult  


Keyword,  defined at i0/drat.i   line 486

SEE drat_amult

drat_gate


    func drat_gate(times) { extern gb, gav;  ... }  
 or drat_gate=   


supplies a gate (to make gated images) for the snap function.  
For a simple gate, the drat_start and drat_stop options will  
be more efficient than drat_gate.  
The input to drat_gate is the list of dump times; the output  
should be the "effective dt" for each of these dumps.  This is  
the product of the actual time interval and the gate transparency;  
the sum of the return vector is the gate time.  See the default_gate  
and gaussian_gate functions for examples.  
Note that the gb and gav arrays read from the history file are  
available as external variables, in case the gate transparency is  
frequency dependent.  
Keyword,  defined at i0/drat.i   line 654

SEE ALSO: snap, drat_backlight, drat_channel, apply_funcs, drat_start,
drat_stop, gaussian_gate, default_gate

drat_gav


    drat_gav  


Keyword,  defined at i0/drat.i   line 447

SEE drat_rt

drat_gb


    drat_gb  


Keyword,  defined at i0/drat.i   line 447

SEE drat_rt

drat_glist


    drat_glist  


if non-nil, an index list into the final dimension of akap and ekap.  
Only these groups will be read from disk and used in the transport  
calculation.  All other options which depend on "ngroup" or "gav"  
should use numberof(DRAT_GLIST) or gav(DRAT_GLIST) instead.  The  
"gb" group boundary array is not well-defined in this case, since  
the group boundaries need not be contiguous.  The best strategy is  
to save drat_glist and the original gb array.  
DRAT_GLIST must be a 1-D, 1-origin index list.  (1-origin even if  
gav and gb are not 1-origin, since use_origins(0) will be in effect  
when DRAT_GLIST is used.)  The streak function will be most efficient  
if DRAT_GLIST is strictly increasing.  
Keyword,  defined at i0/drat.i   line 533

SEE ALSO: integ_linear, integ_flat

drat_nomilne


    drat_nomilne  


Keyword,  defined at i0/drat.i   line 551

SEE drat_linear

drat_oadjust


    drat_oadjust  


Keyword,  defined at i0/drat.i   line 675

SEE drat_ocompute

drat_ocompute


    func drat_ocompute(file, time) { extern opac, source; ...}  
 or drat_ocompute=   


   and func drat_oadjust(file, time) { extern opac, source; ...}  
    or drat_oadjust=   
supply opacities from a source other than the file.drat_akap and  
file.drat_ekap, or adjust these values.  You need to be cognizant of  
the drat_glist option (see get_kaps source code).  
DRAT_OCOMPUTE must set opac and source entirely on its own;  
DRAT_OADJUST will be called afterwards.  
The default DRAT_OCOMPUTE (default_ocompute) reads drat_akap and  
drat_ekap from FILE, optionally extracting drat_glist, and places  
them in opac and source.  
DRAT_OADJUST is free to modify opac and source them at will; the  
default DRAT_OADJUST is nil, which means no adjustment.  
Any opacity or emissivity multipliers will be applied after  
DRAT_OADJUST, as will the point centering operation if necessary  
(DRAT_OADJUST should return zone centered opacities).  
Keyword,  defined at i0/drat.i   line 675

drat_omult


    drat_omult  


Keyword,  defined at i0/drat.i   line 486

SEE drat_amult

drat_quiet


    drat_quiet  


By default, Drat prints the total number of records it will process,  
and the number of the record it is currently processing.  If drat_quiet  
is non-nil and non-zero, the printout is supressed.  
Keyword,  defined at i0/drat.i   line 712

drat_rt


    drat_rt, drat_zt, drat_ireg,  
    drat_akap, drat_ekap,  
    drat_isymz,  
    drat_khold, drat_lhold,  
    drat_gb, drat_gav  


can be set to strings other than "rt", "zt", etc. (their default  
values) to force the streak, snap, and streak_save routines to use  
alternative names to look up these quantites in the history file.  
The following 4 variables are NOT optional:  
(rt, zt) must be a 2-D mesh in cylindrical coordinates  
akap is a mesh-by-ngroup array of absorption opacities, in units  
     of reciprocal length (1/rt or 1/zt)  
ekap is a mesh-by-ngroup array of source functions, in (arbitrary)  
     specific intensity units  
The akap and ekap arrays must be zone centered; the first row and  
column of akap and ekap will be ignored.  
The remaining variables are all optional -- set the drat_.. variable  
to [] to ignore them completely.  Otherwise, they will be ignored if  
they are not present in the history file, and used as follows  
otherwise:  
ireg is a mesh-size region number array (zone centered as akap and  
     ekap).  Zones where ireg==0 do not exist.  
isymz is non-zero if the problem has reflection symmetry about z=0,  
     zero otherwise.  The drat_symmetry option overrides this value.  
khold and lhold are mesh indices specifying "hold lines" --  
     khold is an index into the first dimension of (rt,zt), and  
     lhold is an index into the second dimension of (rt,zt).  
     These are used only if the drat_linear option is specified.  
gb and gav are, respectively, the group boundary energies and group  
     center energies.  These are used by the snap and streak_save  
     functions.  
Keyword,  defined at i0/drat.i   line 447

SEE ALSO: streak, snap, streak_save, drat_symmetry, drat_linear

drat_start


    drat_start, drat_stop  


if non-nil, specify the minimum and maximum dump times which will  
be considered by the streak, snap, or streak_save functions.  
Keyword,  defined at i0/drat.i   line 520

drat_static


    drat_static  


if non-nil, a list of strings representing variable names in the  
input file which the streak_save function should copy to the  
output file.  
Keyword,  defined at i0/drat.i   line 569