PDM2

Name

pdm2

Purpose (one Line)

Period search by phase dispersion minimization ($\chi^2$ based)

Description

This routine computes a Chi^2 statistic for period searching
in time-series data loosely based on the technique described by
Stellingwerf, ApJ, 224, pp. 953-960 (1978).
This algorithm is discused more in Buie and Bus, Icarus, 100, 288-294
(1992) "Physical Observations of (5145) Pholus".

Calling Sequence

pdm2,t,x0,sigx0,freq1,freq2,dfreq,freq,period,chi2

Inputs

t - independent variable (usually time)
x0 - dependent variable (usually magnitude or intensity)
sigx0 - Uncertainty on x.
freq1 - Lower limit to frequency to compute statistic (units=[1/t])
freq2 - Upper limit to frequency to compute statistic (units=[1/t])
dfreq - Frequency interval. (units=[1/t])

Optional Input Parameters

Keyword Parameters

NBINS - Number of bins (default = 80)
SILENT - Flag, if set, inhibits all printed output.

Outputs

freq - Frequency vector.
period - inverse frequency.
chi2 - Chi^2 statistic.
avgyes - Average number of points contained within non-empty bins.
nempty - Total number of empty bins.

Common Blocks

Side Effects

Restrictions

Procedure

Modification History

Written 1992 Feb 11, by Marc W. Buie, Lowell Observatory
94/08/26 - MWB - added NBINS keyword
94/10/04 - MWB - moved cr to front of print statement (v3.6 bug workaround)
96/07/01 - MWB - added SILENT keyword