genwave: Interactively generate a wavelength set.

Package: synphot

Usage

genwave output minwave maxwave dwave

Description

This task creates a wavelength set based on user specified values for the minimum and maximum of the desired wavelength range and the sampling interval. The sampling interval may be expressed in terms of Angstroms per pixel ('dwave') or in terms of km/s/pixel ('dvelocity'). The default is to use the value passed to the 'dwave' parameter, unless the value of 'dwave' is INDEF.

Parameters

output [file name]

File name for the wavelength table that will be created by this task. The wavelength table is a set of sampling points for both spectral flux and throughput transmission, and is used by various tasks in the 'synphot' package.

minwave [real]

Minimum value for wavelength range (in Angstroms).

maxwave [real]

Maximum value for wavelength range (in Angstroms).

dwave = INDEF [real]

Wavelength interval between sampling points (in Angstroms/sample). The value of this parameter is ignored if it is set to INDEF, and the value of 'dvelocity' is used instead.

(dvelocity = INDEF) [real]

Velocity interval between sampling points (in km/s/sample). If set to INDEF, this parameter is ignored and the wavelength interval is calculated from the value of 'dwave'.

(wavecol = "WAVELENGTH") [string]

Name for the column in 'waveset' that will contain the wavelength values. Values written to this column will be in Angstrom units. The default column name "WAVELENGTH" creates a wavelength table that can be used by other task in the synphot package.

Examples

1. Generate a wavelength set having a range of 3000 to 8000 Angstroms, and an interval of 10 A per sample. Results will be written to the column 'WAVELENGTH' in the table file 'samplset.tab'.

sy> genwave samplset.tab 3000. 8000. 10.

2. Generate a wavelength set having the same range as above, but set the sampling interval to be 100 km/s/pixel.

sy> genwave samplset.tab 3000. 8000. INDEF dv=100.

References

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

See also

Type "help synphot opt=sys" for a description of table structures used by synthetic photometry tasks.