Configuration¶
There are two types of configuration settings: those dedicated purely to measurements, and those related to the source extraction process and to global operations of SourceXtractor++.
Measurement settings can be rather complex and require a Python configuration script (see the Measurement section).
Global configuration settings may be changed using command-line options (prefixed with a --), however a configuration file is often more convenient for storing settings that do not change from run to run.
Note
Command-line options can be abbreviated, provided that there is no more than one full matching keyword.
Example: --config-file=foo.conf may be abbreviated as --conf=foo.conf.
The configuration file¶
SourceXtractor++ searches for the configuration file at the beginning of a run, starting from system repositories (which makes it possible to apply specific, system-wide configuration settings), to the current repository. Each time it is run, SourceXtractor++ looks for a configuration file. The name of a dedicated configuration files is given with:
$sourcextractor++ --config-file sepp.config
Creating a configuration file¶
SourceXtractor++ dumps all parameters with their default values into a configuration files with:
$sourcextractor++ --dump-default-config > my_sepp.config
Format of the configuration file¶
Configuration instructions follow the <option> = <value> format.
There must be no more than one <option> = <value> instance per line.
Comments must be preceded with a #. Boolean parameters are set/unset with 1/0 such as: output-flush-unsorted=1, and the individual parameters of a parameter list are separted with a “,” such as output-properties=SourceIDs,PixelCentroid,WorldCentroid
Configuration parameter list¶
Here is a complete list of all the configuration parameters known to SourceXtractor++. Please refer to the next sections for a detailed description of their meaning.
Option |
Default |
Use |
|---|---|---|
Generic options |
||
|
Print version string |
|
|
Produce help message |
|
|
— |
Name of a configuration file |
|
|
Log level: FATAL, ERROR, WARN, INFO (default), DEBUG |
|
— |
Name of a log file |
|
List the possible output properties for the given input parameters and exit |
|
|
Show the columns created for each property |
|
|
Show the columns created for each property, for the given configuration |
|
|
5 |
Minimal interval to wait before printing a new log entry with the progress report |
|
Disable progress bar display |
|
Auto (Kron) photometry options |
||
|
2.5 |
Scale factor for AUTO (Kron) photometry |
|
3.5 |
Minimum radius for AUTO (Kron) photometry |
Background modelling |
||
|
64 |
Background mesh cell size to determine a value |
|
3 |
Background median filter size |
Check images |
||
|
— |
Path to save the model fitting check image |
|
— |
Path to save the model fitting residual check image |
|
— |
Path to save the background check image |
|
— |
Path to save the variance check image |
|
— |
Path to save the segmentation check image |
|
— |
Path to save the partition check image |
|
— |
Path to save the grouping check image |
|
— |
Path to save the filtered check image |
|
— |
Path to save the thresholded check image |
|
— |
Path to save the auto aperture check image |
|
— |
Path to save the aperture check image |
|
— |
Path to save the moffat check image |
|
— |
Path to save the PSF check image |
Cleaning |
||
|
Enable the cleaning of sources (remove false detections near bright objects) |
|
|
3 |
Minimum # of pixels above threshold |
Detection image |
||
|
— |
Background value to be subtracted from the detection image |
|
1.5 |
Detection threshold above the background |
|
|
Segmentation algorithm to be used. Currently LUTZ is the only choice |
|
Disables filtering |
|
|
— |
Loads a filter |
|
— |
Path to a fits format image to be used as detection image. |
|
0 |
Detection image gain in e-/ADU (0 = infinite gain) |
|
Detection image flux scale |
|
|
Detection image saturation level (0 = no saturation) |
|
|
1 |
Interpolate bad pixels in detection image |
|
5 |
Maximum number if pixels to interpolate over |
External flag options |
||
|
— |
FITS file containing the external flag |
|
— |
The combination type of the external flag (OR, AND, MIN, MAX, MOST) |
Extraction |
||
|
3 |
Minimum # of pixels above threshold |
|
Enables the use of attractors for partitioning |
|
Grouping |
||
|
|
Grouping algorithm to be used (NONE, MOFFAT) |
|
0.02 |
Threshold used for Moffat grouping. |
Magnitude |
||
|
0 |
Magnitude zero point calibration |
Measurement config |
||
|
— |
Measurements Python configuration file |
|
— |
Parameters to pass to Python via sys.argv |
Memory usage |
||
|
512 |
Maximum memory used for image tiles cache in megabytes |
|
256 |
Image tiles size in pixels |
Model Fitting |
||
|
1000 |
Maximum number of iterations allowed for model fitting |
Multi-threading |
||
|
4 |
Number of worker threads (0=disable all multithreading) |
Multi-thresholding |
||
|
Activate multithreshold partitioning |
|
|
32 |
of thresholds |
|
3 |
Minimum area in pixels to consider partitioning |
|
0.005 |
Minimum contrast for partitioning |
Output configuration |
||
|
— |
The file to store the output catalog |
|
|
The format of the output catalog, one of ASCII or FITS |
|
|
The output properties to add in the output catalog |
Plugin configuration |
||
|
— |
Path to a directory that contains the plugins |
|
— |
Defines a plugin to load (without file extension). Can be used multiple times |
Variable PSF |
||
|
— |
PSF image file (FITS format) |
|
— |
Generate a Gaussian PSF with the given full-width half-maximum (in pixels) |
|
— |
Generate a Gaussian PSF with the given pixel sampling step size |
Weight map |
||
|
— |
Path to a FITS format image to be used as weight image |
|
0 |
Is the weight map provided as absolute values or relative to background |
|
|
Weight image type (BACKGROUND, RMS, VARIANCE, WEIGHT) |
|
1 |
Weight map scaling factor |
|
— |
Threshold for pixels to be considered bad pixels. In same units as weight map. |
|
1 |
Use object symmetry to replace pixels above the weight threshold for photometry |