section i of routines in drat.i

functions in drat.i - i

integ_flat


    integ_flat(opac, source, rays, mesh, slimits)  
 or integ_flat(opac, source, ray_paths)  


returns ngroup-by-2-by-nrays result, where result(,1,..) is  
the transparency factors, and result(,2,..) is the self-emission  
for each group on each ray.  The input OPAC and SOURCE are the  
opacity (an inverse length) and the source function (a specific  
intensity).  They are mesh-by-ngroups zone centered arrays.  The  
result has the same units as SOURCE.  
In the second form, RAY_PATHS was returned by the track_rays  
function.  
Interpreted function, defined at i0/drat.i   line 1111

SEE ALSO: integ_linear, track_rays, form_mesh, streak, snap

integ_linear


    integ_linear(opac, source, rays, mesh, slimits)  
 or integ_linear(opac, source, ray_paths)  


returns ngroup-by-2-by-nrays result, where result(,1,..) is  
the transparency factors, and result(,2,..) is the self-emission  
for each group on each ray.  The input OPAC and SOURCE are the  
opacity (an inverse length) and the source function (a specific  
intensity).  They are mesh-by-ngroups arrays; OPAC is zone centered,  
while SOURCE is point centered (using pcen_source).  The result  
has the same units as SOURCE.  
In the second form, RAY_PATHS was returned by the track_rays  
function.  
The integ_linear routine assumes that the SOURCE function varies  
linearly between the entry and exit points from each zone.  This  
assumption is poor near the turning point, and causes the result  
to be a discontinuous function of the ray coordinates, unlike the  
integ_flat result.  
Interpreted function, defined at i0/drat.i   line 1154

SEE ALSO: pcen_source, integ_flat, track_rays, form_mesh, streak, snap

is_present


    is_present(get_vars(f), name)  


returns 1 if variable NAME is present in file F, 0 if not.  
Interpreted function, defined at i0/drat.i   line 891