NAME

showfiles -- Print a list of filenames used in a synphot expression

USAGE

showfiles expr

DESCRIPTION

This task produces a list of filenames used in evaluating a synphot expression. The purpose of this task is to allow the user to better understand the results that synphot produces by listing the files that go into computing this result.

There are several functions in synphot expressions which use files. The principal functions are the band() and cat() functions. The band() function evaluates the combined throughput for an observation mode by multiplying the individual throughputs of the components in the optical path together. These component throughputs are stored in SDAS tables. This task shows you the component tables that synphot uses for a specified observation mode. The cat() and icat() functions select a spectrum from a catalog of spectra. This task prints the name of the spectrum or spectra. This task will also print he names of files used by other functions, such as the grid(), spec(), and thru() functions, as well as filenames embedded in the synphot expression.

PARAMETERS

expr [string]

An expression used by the synphot expression evaluator to compute a synthetic spectrum or passband. If the expression consists of a single call to the band() function, only the arguments to the function need be given. For example, the expression "band(wfpc,f555w)" can also be given as "wfpc,f555w". The syntax and functions available in the synphot expression evaluator are explained in the calcspec help file and the Synphot User's Guide.

(refdata = "") [pset name]

Parameter set for reference data used in calculations. This pset contains the following parameters:

area = 45238.93416:  HST telescope area in cm**2.

grtbl = "mtab$*.tmg":  HST graph table.  By default, this
        uses the most recent version. 

cmptbl = "mtab$*.tmc"  Instrument component table.  By 
        default, this uses the most recent version.

EXAMPLES

1. Create the list of component table names for the FOC f/96 observing mode:

  sy> showfiles foc,f/96

2. Show the files used to renormalize the vega spectrum in the wfpc,f55w passband:

  sy> showfiles "rn(crcalspec$alpha_lyr_stis_002.fits,band(wfpc,f555w),10,stmag)"

REFERENCES

Written by B.Simon based on XCAL code written by Keith Horne

SEE ALSO

calcspec