Re: Software re-binned PD data

2019-09-27 Thread Reinhard Kleeberg
The problem of falsified counting statistics (deviating from Poisson distribution) sometimes arises even from (wrong) conversion of 0D detector data (typically when originally cps have been stored and the counting time got lost in the conversion), and is quite common when 1D detector data are

Re: Software re-binned PD data

2019-09-27 Thread Jonathan WRIGHT
If this rule is broken, such as the mode in FIT2D that smooths patterns by pixel-splitting) then one introduces correlation between points in the pattern Hi Brian, your comment has triggered me it seems :-) For SAXS and PDF it could be better to under-sample the data (see end), but for

Re: RE: Software re-binned PD data

2019-09-27 Thread Alan Hewat
Tony. If you want the statistics to be the same as for larger steps you should be adding the counts from your PSD channels, not averaging them. That said, with an x-ray PSD you perhaps have so much intensity that uncertainties in your refined parameters due to counting statistics may be small

Re: RE: Software re-binned PD data

2019-09-27 Thread Matthew Rowles
Hi Tony If you want to have a look at what the uncertainties are doing, then try scanning over a peak a couple of dozen times (maybe with a few different mA settings on the tube, maybe with some different step times) to collect a range of different intensities. The standard deviation of the "raw"