Projects

SIGSPEC is called by the command line

SigSpec <project>

where <project> is the name (or path, if desired) of the SIGSPEC project. Before running the program, the user has to provide

1. a directory <project> used for the output,
2. a time series input file (see ``The time series input file'', p.).

The project directory and the time series input file have to be located in the same folder. The project directory need not be empty.

Caution: SIGSPEC overwrites existing output files!

There are two conventions for denominating input files.

1. The standard method is to pass only one time series input file to the program. SIGSPEC expects the file to be named <project>.dat.
2. For an all-in-one analysis of multiple time series input files, i.e., for running SIGSPEC in MultiFile mode, a leading six-digit index is expected. In this case, the first file shall be named 000000.<project>.dat, the next file is 000001.<project>.dat, and so on. For more information on the MultiFile mode, please refer to ``MultiFile mode'', p..

Furthermore, the user may pass a set of specifications to SIGSPEC by means of a file <project>.ini (see ``The .ini file'', p.). This file is expected in the same folder as the time series input file and the project directory. For specifications not given by the user, defaults are used.

Example. The sample project SigSpecNative provides a run without any additional options. The command line is SigSpec SigSpecNative. The sample input file SigSpecNative.dat (381 data points) represents V magnitudes of IC4996#89 (Zwintz et al. 2004; Zwintz & Weiss 2006).

The screen output produced by typing SigSpec SigSpecNative at runtime starts with a standard header.

 SSSSSS  ii          SSSSSS
SS    SS            SS    SS
SS       ii  gggg g SS       p pppp   eeeee   ccccc
SS       ii gg   gg SS       pp   pp ee   ee cc   cc
 SSSSSS  ii gg   gg  SSSSSS  pp   pp ee   ee cc
      SS ii gg   gg       SS pp   pp eeeeeee cc
      SS ii gg   gg       SS pp   pp ee      cc
SS    SS ii gg   gg SS    SS pp   pp ee   ee cc   cc
 SSSSSS  ii  gggggg  SSSSSS  pppppp   eeeee   ccccc
                 gg          pp
            gg   gg          pp
             ggggg           pp


SIGnificance SPECtrum
Version 2.0
************************************************************
by Piet Reegen
Institute of Astronomy
University of Vienna
Tuerkenschanzstrasse 17
1180 Vienna, Austria
Release date: August 18, 2009

SIGSPEC processes the command line, checks whether a project directory SigSpecNative is present, and searches for a file SigSpecNative.ini (see ``The .ini file'', p.). Since there is no such file present, four warning messages are produced.

*** start **************************************************

command line interface
Checking availability of project directory SigSpecNative...
project directory SigSpecNative ok.
loading .ini file

Warning: IniFile_SSCols 001
         Failed to open .ini file.


Warning: IniFile_WCols 001
         Failed to open .ini file.


Warning: IniFile_LoadIni 001
         Failed to open .ini file.


Warning: IniFile_Cind 001
         Failed to open .ini file.

The next task is to load the input file SigSpecNative.dat. SIGSPEC provides the number of rows, the time interval width, and the standard deviation of the observable.

*** loading time series input file(s) **********************

SigSpecNative.dat

*** time series properties *********************************

points 381, time base 9.17532, rms dev 0.00449592

The next section contains the specifications for the DFT and significance spectra to be calculated.

*** preparing to run SigSpec *******************************

Rayleigh frequency resolution             0.1089880382935977
oversampling ratio                       20.0000000000000000
frequency spacing                         0.0054494019146799
lower frequency limit                     0.0000000000000000
upper frequency limit                   100.4651736990383739
Nyquist coefficient                       0.5000000000000000
number of frequencies                 18437

As SIGSPEC performs the prewhitening sequence, a list of detected signal components is displayed. The screen output contains the index of the identified component (a line number), the sig, the time-domain rms deviation before prewhitening the corresponding signal, and the csig. The last line contains an insignificant component that meets the breakup condition. In the present example, the default breakup condition (the sig to drop below 5) is applied, which is satisfied in the fourth iteration, where the maximum sig is 4.10802.

*** running SigSpec ****************************************

   1 freq 3.13205  sig 9.54539  rms 0.00449592  csig 9.54539
   2 freq 3.98471  sig 7.43085  rms 0.00422861  csig 7.42753
   3 freq 5.40684  sig 5.30164  rms 0.0040257  csig 5.2984
   4 freq 17.3677  sig 4.13698  rms 0.00388775  csig 4.10802

On exit, SIGSPEC displays a good-bye message.

Finished.

************************************************************

Thank you for using SigSpec!
Questions or comments?
Please contact Piet Reegen ([email protected])
Bye!

Figure 1: Black circles: light curve for the sample project SigSpecNative. Line: fit formed by three significant signal components (as listed in the file SigSpecNative/result.dat). Grey dots: residuals after prewhitening of three significant signal components (file SigSpecNative/residuals.dat).

Figure 2: Grey: Fourier spectra for the sample project SigSpecNative. Left: significance spectra. Right: DFT amplitudes. Top: original spectra, without prewhitening (file SigSpecNative/s000000.dat). Bottom: residual spectra, with three significant signal components prewhitened (file SigSpecNative/resspec.dat). In the top panels, the significant components are indicated by dots with dashed drop lines (file SigSpecNative/result.dat). The default sig threshold of 5 is represented by a horizontal dashed line in the left panels.

If no special output is selected in a file SigSpecNative.ini, SIGSPEC produces the following output files in the project directory SigSpecNative:

• s000000.dat: DFT and significance spectrum of the original time series (without any prewhitening),
• result.dat: list of significant signal components detected in the time series,
• residuals.dat: residual time series after prewhitening all significant signal components listed in result.dat,
• resspec.dat: DFT and significance spectrum of the residual time series residuals.dat.

Fig.1 contains the sample input SigSpecNative.dat, the multisine fit to the time series according to the list of significant signal components in SigSpecNative/result.dat, and the residuals after subtracting the fit from the input time series (file SigSpecNative/residuals.dat). Fig.2 refers to the frequency domain: the DFT spectrum of the initial time series SigSpecNative/s000000.dat, the three significant signal components contained in SigSpecNative/result.dat, and the residual spectrum in the file SigSpecNative/resspec.dat. For detailed information on the contents of the output files, please refer to ``Default Output'', p..

Furthermore, the user may pass a set of specifications to SIGSPEC in a file <project>.ini (see ``The .ini file'', p.). For specifications not given by the user, defaults are used.