STScI Logo

orderphase stsdas.analysis.timeseries



orderphase -- Order time series observations by fractional phase.


orderphase infile outfile phasefile timefile inmask outmask period epoch0 period_unit epoch0_spec


For each observation, the phase is computed from the time of measurement, the period of variability, and the epoch date. A single-cycle light curve is produced by reordering all points according to their fractional phase. The data can be examined as a single-cycle light curve to evaluate the choice of period or to remove discrepant data. Both an output science file (containing the single-cycle light curve data) and an independent variable (IV) file (containing the fractional phases) are produced.

Data masks associated with the input time series are accommodated, and a corresponding data mask will be available for the output data in which fractional phase is the independent parameter.

NOTE: Before using this task, it may be necessary to correct the input time series for the effect of the light delay time (using the delaytime task). This correction is important if the light delay time is a significant fraction of the period of variablility. For example, pulsar data should be reduced to the solar system barycenter before invoking synchronous co-addition.


infile = "" [string]
Name of the input science data file (templates are allowed for this and the following file name parameters).
outfile = "" [string]
Name of the output science data file.

If the number of input files is the same as the number of output files, then each input file will produce one corresponding output file and one phase file. If there are several input files but only one output file, the result will be combined into a single output file and phase file.

phasefile = "" [string]
Output phase data file name.
timefile = "" [string]
Input time data file name (optional).

If an input time file is used (most likely from the delaytime task), data in the time file are used to calculate the phase directly. Pixel values in the time file are seconds from the first pixel; the epoch (in MJD) of the first pixel is specified in the header keyword REFMJD. If there is no input time file, the time information of CD1_1 and EXPSTART in the input science file are used to construct a linear time array.

inmask = "" [string]
Input science mask file name (optional).
outmask = "" [string]
Output science mask file name (optional).
period = [double, min > 0]
Variation period of the observed time series in the unit specified by the period_unit parameter.
epoch= [double]
Epoch at zero phase. This epoch should be set as close to the data epoch as possible otherwise, if the period is very short, a warning message will appear and the phases may be inaccurate.
period_unit = "s" [string, allowed values = s | m | h | d]
Unit of period, s = seconds, m = minutes, h = hours, d = days.
epoch0_spec = "mjd" [string, allowed values = mjd | pix]
Zero phase specification. If this parameter is set to "mjd", then the numerical value of epoch0 is taken as the zero epoch phase in MJD. If this parameter is set to "pix", then the numerical value specified in epoch0 is the pixel number corresponding to the zero phase. In the case of multiple input files, the pixel number refers to the first file.


1. Order the phases of data in the input file data1.d0h and put the result in the science file dataout.d0h and phase file dataphase.d0h. Assume the period is 2.34 seconds and the epoch of zero phase is MJD 47700.2:

ti> orderphase infile="data1.d0h" outfile="dataout.d0h" \
>>> phasefile="dataphase.d0h" period=2.34 \
>>> epoch0=47700.2 period_unit="s" epoch0_spec="mjd"




delaytime, coadd

Source Code · Package Help · Search Form · STSDAS