(Integer parameter; d/f=5; range >1)
This is one of the most important global parameters of XRONOS: it is used to define the way in which the error bars of the results of XRONOS applications are calculated. If the specified number of the intervals per frame is higher than the value of the parameter (default=5), the error bars of the result points are evaluated by using the standard deviation of the average of the result points (based on the measured scatter). Otherwise the error bars are evaluated by propagating the theoretical error bars through the averaging process. Note that for several XRONOS applications (e.g. acf, ccf) only the former way of evaluating error bars is available.
For example, for the default value of 5 and application psd: (a) if a frame is specified to be the average of 5 or less power spectra, then the error bars in the average power spectrum will be calculated by propagating through the average the theoretical error bars associated to each power spectrum (in turn obtained from the relevant chi-square distribution); (b) on the other hand if a frame is specified to be the average of 6 or more power spectra, then the error bars in the average power spectrum will be calculated by evaluating the standard deviation of the average power for each frequency.
By adjusting the value of this global parameter it is possible, e.g. to evaluate error bars as in (a), also in the case in which a large number of intervals per frame has been specified. Values < 5 are not recommended (at least 5-6 measures are necessary to reliably evaluate the standard deviation of the average from the scatter around it).