CREFRAME

Generates a test two-dimensional NDF with a selection of several forms

Description:

This application creates a two-dimensional output NDF  containing artificial data of various forms (see Parameter MODE). The output NDF can, optionally, have a VARIANCE component describing the noise in the data array (see Parameter VARIANCE), and additionally a randomly generated pattern of bad pixels (see Parameter BADPIX). Bad columns or rows of pixels can also be generated.

Usage:

creframe out mode [lbound] [ubound]
 
mean=? background=? distrib=? max=? min=? ngauss=? seeing=? mean=? sigma=? high=? low=?

  mode

Parameters:

BACKGROUND = _REAL (Read)
Background intensity to be used in the generated data array. Must not be negative. (GS mode).
BADCOL = _INTEGER (Read)
The number of bad columns to include. Only accessed if Parameter BADPIX is TRUE. The bad columns are distributed at random using a uniform distribution. [0]
BADPIX = _LOGICAL (Read)
Whether or not bad pixels are to be included. See also Parameters FRACTION, BADCOL and BADROW. [FALSE]
BADROW = _INTEGER (Read)
The number of bad rows to include. Only accessed if Parameter BADPIX is TRUE. The bad rows are distributed at random using a uniform distribution. [0]
DIRN = _INTEGER (Read)
Direction of the ramp. 1 means left to right, 2 is right to left, 3 is bottom to top, and 4 is top to bottom. (RA mode)
DISTRIB = LITERAL (Read)
Radial distribution of the Gaussians to be used (GS mode). Alternatives weightings are:

  • "FIX" –- fixed distance, and

  • "RSQ" –- one over radius squared.

["FIX"]

FRACTION = _REAL (Read)
Fraction of bad pixels to be included. Only accessed if BADPIX is TRUE. [0.01]
HIGH = _REAL (Read)
High value used in the generated data array (RA and RL modes).
LBOUND( 2 ) = _INTEGER (Read)
Lower pixel bounds of the output NDF. Only accessed if Parameter LIKE is set to null (!).
LIKE = NDF (Read)
An optional template NDF which, if specified, will be used to define the bounds for the output NDF. If a null value (!) is given the bounds are obtained via Parameters LBOUND and UBOUND. [!]
LOGFILE = LITERAL (Read)
Name of a log file in which to store details of the Gaussians added to the output NDF (GS mode). If a null value is supplied no log file is created. [!]
LOW = _REAL (Read)
Low value used in the generated data array (RA and RL modes).
MAX = _REAL (Read)
Peak Gaussian intensity to be used in the generated data array (GS mode).
MEAN = _REAL (Read)
Mean value used in the generated data array (FL, RP and GN modes).
MIN = _REAL (Read)
Lowest Gaussian intensity to be used in the generated data array (GS mode).
MODE = LITERAL (Read)
The form of the data to be generated. The options are as follows.

  • "RR" –- Uniform noise between 0 and 1.

  • "RL" –- Uniform noise between specified limits.

  • "BL" –- A constant value of zero.

  • "FL" –- A specified constant value.

  • "RP" –- Poisson noise about a specified mean.

  • "GN" –- Gaussian noise about a specified mean.

  • "RA" –- Ramped between specified minimum and maximum values and a choice of four directions.

  • "GS" –- A random distribution of two-dimensional Gaussians of defined FWHM and range of maximum peak values on a specified background, with Poissonian noise. There is a choice of spatial distributions for the Gaussians: fixed, or inverse square radially from the array centre. (In essence it is equivalent to a simulated star field.) The x-y position and peak value of each Gaussian may be stored in a log file, a positions list catalogue, or reported on the screen. Bad pixels may be included randomly, and/or in a column or line of the array.

NGAUSS = _INTEGER (Read)
Number of Gaussian star-like images to be generated (GS mode).
OUT = NDF (Write)
The output NDF.
OUTCAT = FILENAME (Write)
An output catalogue in which to store the pixel co-ordinates of the Gausians in the output NDF (GS mode). If a null value is supplied, no output positions list is produced. [!]
SEEING = _REAL (Read)
Seeing (FWHM) in pixels (not the same as the standard deviation) (GS mode).
SIGMA = _REAL (Read)
Standard deviation of noise to be used in the generated data array (GN mode).
TITLE = LITERAL (Read)
Title for the output NDF. ["KAPPA - Creframe"]
UBOUND( 2 ) = _INTEGER (Read)
Upper pixel bounds of the output NDF. Only accessed if Parameter LIKE is set to null (!).
VARIANCE = _LOGICAL (Read)
If TRUE, a VARIANCE component is added to the output NDF representing the noise added to the field. If a null (!) value is supplied, a default is used which is TRUE for modes which include noise, and FALSE for modes which do not include any noise. [!]

Examples:

creframe out=file ubound=[128,128] mode=gs ngauss=5 badpix badcol=2 max=200 min=20 background=20 seeing=1.5
Produces a 128×128 pixel data array with 5 gaussians with peak values of 200 counts and a background of 20 counts. There will be two bad columns added to the resulting data.

Notes:

Implementation Status: