Usage¶
The command line interface help¶
You start specstack from a terminal. specstack comes with a command line interface which includes a ‘help’ that you can display in your terminal using the help command. It must be called like this:
[user@machine]$ specstack --help
This command will display the help of the program:
usage: specstack [-h] [-s S] [-p] [--method METHOD] [-f F]
speclist normlimits bin
specstack V19.4.0, R. Thomas, 2018, ESO, This program comes with ABSOLUTELY NO
WARRANTY; and is distributed under the GPLv3.0 Licence terms.See the version
of this Licence distributed along this code for details.
positional arguments:
speclist File with col1 = spectra names, col2 = redshift
normlimits l1 and l2 in angstrom where the spectra will be normalised
bin Binning of the stacked spectrum
optional arguments:
-h, --help show this help message and exit
-s S Sigma we use for the clipping, default=3
-p If plot at the end
-f F Name of the final file
specstack has few optionnal arguments and 3 mandatory arguements. You can not start specstack without any argument:
Mandatory arguments¶
- speclist: This is the file that contains the list of spectra you want to stack. This files should have two columns:
- the spec column: name of the spectrum file to use
- the redshift column: redshift of the spectrum
- The header of the file should be ‘#redshift spec’. The names of the columns should be there.
Example:
#redshift spec
3.5 spec1.txt
3.7 spec2.txt
3.65 spec3.txt
. .
. .
. .
Warning
Each spectrum should be an ascii file with (wavelength-flux) columns. Wavelength should be in Angstrom.
- normlimits: This is where the spectra are going to be normalized. It consists of two wavelength in angstrom, separated by a coma. Example: 1020,1120.
- bin: This is the final binning, in angstrom, of the spectrum.
Optional arguments¶
- -h and ‘- -help’: Display this help in the terminal.
- -s: The program uses a simgal clipping algorithm to compute the stack. The default value is 3sigma but you can as well use a different number of sigma if you want too. Example: -s 4 will use a 4-sigma clipping.
- -p: If you want to see the result of the stacking as a plot directly after the computation.
- -f: By default the stacked spectrum is saved in a text file with wavelength-stackflux-standard deviation. The file is by default called ‘stacked.txt’. But if you want to give another name you can use that option. Example: -f final_stack.txt. This way the final file will be called final_stack.txt.