mkspec: Generate an artificial spectrum

Package: irs

Usage

mkspec image_name image_title ncols nlines function

Parameters

image_name: The name to be given to the image file

image_title: A character string to be used to describe the image

ncols: The number of pixels in the spectrum (the length of the image).

nlines: The number or lines (rows) in the image.

function: An indicator specifying the form of the spectrum: 1 - a constant, 2 - a ramp running from start_level to end_level, 3 - a black body extending in wavelength (Angstroms) from start_wave to end_wave at a given temperature (in degrees K).

constant: The value to be assigned to the spectrum if function=1 (constant).

start_level: The starting value to be assigned to the spectrum at pixel 1 if function=2 (ramp).

end_level: The ending value of the spectrum assigned at pixel=ncols if function=2.

start_wave: The wavelength (Angstroms) assigned to pixel 1 if function=3 (Black Body).

end_wave: The wavelength (Angstroms) assigned to the last pixel if function=3.

temperature: The black body temperature (degrees K) for which the spectrum is to be created if function=3.

Description

An artificial image is created with the specified name and length. The image may have a constant value (function=1), or may be a ramp with either positive or negative slope (function=2), or may be a black body curve (function=3).

Only those parameters specific to the functional form of the image need be specified. In all cases the parameters image_name, image_title, ncols, nlines, and function are required. If function=1, parameter constant is required; if function=2, start_level and end_level are required; if function=3, start_wave, end_wave, and temperature are required.

All black body functions are normalized to 1.0 at their peak intensity which may occur at a wavelength beyond the extent of the generated spectrum.

NOTE THAT THIS TASK IS OBSOLETE AND ARTDATA.MK1DSPEC SHOULD BE USED. In particular this task does not set the header dispersion coordinate system.

Examples

cl> mkspec allones "Spectrum of 1.0" 1024 1 1 constant=1.0
cl> mkspec ramp "From 100.0 to 0.0" 1024 64 2 start=100 \
>>> end=0.0
cl> mkspec bb5000 "5000 deg black body" 512 1 3 start=3000 \
>>> end=8000 temp=5000

Revisions

MKSPEC V2.10: This task is unchanged.