Bruce, But the sampling interval is still 1 sec and you can see by my notes that I explicitly give this on the command line for adev1.exe.
OK, I'll have a go at compiling it as it is just a command line program. 73, Steve 2009/4/9 Bruce Griffiths <bruce.griffi...@xtra.co.nz>: > Steve > > Therein lies your problem. > adev1 defaults to a sampling interval of 1 sec. (read the C source code). > TvB's documentation explicitly states that you should supply the > sampling interval. (its a command line argument for adev1.c). > > adev1.c is a simple command line program that uses stdin and stdout so > porting it to a linux command line (non graphical) program should be > straightforward. > You can even use redirection and pipes should you need them. > > You can try porting it to Scilab which is free courtesy of the French > Government. > > > Bruce > > Steve Rooke wrote: >> Bruce, >> >> I set nothing, as indicated in my text, I just delete data points, IE. >> a file of 400000 records now becomes 200000. I'm trying to get my head >> round this as the absolute requirement for continuous data seems >> unneeded. What you have to remember here is that the data set I'm >> working with consists of discrete measurements of the period of each >> pulse. If it was timestamps, then there would be problems. >> >> I don't know how much MATLAB costs but I would guess it is way out of my >> budget. >> >> 73, >> Steve >> >> 2009/4/9 Bruce Griffiths <bruce.griffi...@xtra.co.nz>: >> >>> Steve >>> >>> The data file doesn't include the time interval between samples so do >>> you set this in some way? >>> If so you need to set it to 1s for the unaltered data, to 2s when you >>> take every 2nd sample, and 1s when you take the first 200,000 samples. >>> >>> In principle you could use CANVAS (available on request from USNO - >>> however you may have to wait a few days while they decide whether to >>> grant your request.) for such analysis in Linux but you would then need >>> the Linux version of Matlab. >>> Or you could request that it be compiled for Linux - a fairly simple >>> task if one has the Linux version of Matlab. >>> >>> In principle you should be able to port the m source files to Scilab, >>> but there are some subtle differences between Scilab and Matlab so this >>> may take a while. >>> >>> Bruce >>> >>> Steve Rooke wrote: >>> >>>> Bruce, >>>> >>>> But how does that explain the output of Tom's adev1 program which >>>> still seems to give a a good measurement at tau = 1s? >>>> >>>> 73, >>>> Steve >>>> >>>> 2009/4/8 Bruce Griffiths <bruce.griffi...@xtra.co.nz>: >>>> >>>> >>>>> Steve >>>>> >>>>> If you delete every second measurement then your effective minimum >>>>> sampling time is now 2s and you can no longer calculate ADEV for tau< 2s. >>>>> You can still calculate ADEV for tau = 100,000 sec. >>>>> >>>>> If you delete all but the first 200,000 lines then you can calculated >>>>> ADEV for tau=1sec and up to tau= 25,000 sec with reasonable accuracy. >>>>> >>>>> You shouldn't lose sight of the fact that ADEV and OADEV are both >>>>> estimates of the Allan deviation. >>>>> >>>>> >>>>> Bruce >>>>> >>>>> Steve Rooke wrote: >>>>> >>>>> >>>>>> Tom, >>>>>> >>>>>> I understand fully the points that you have made but I have obviously >>>>>> not made my point clear to all and i apologise for my poor >>>>>> communication skills. >>>>>> >>>>>> This is what I'm getting at: >>>>>> >>>>>> Using your adev1.exe from http://www.leapsecond.com/tools/adev1.htm >>>>>> and processing various forms of gps.dat from >>>>>> http://www.leapsecond.com/pages/gpsdo-sim/gps.dat.gz. >>>>>> >>>>>> C:\Documents and Settings\Steve Rooke\Desktop>adev1.exe 1 <gps.dat >>>>>> >>>>>> ** Sampling period: 1 s >>>>>> ** Phase data scale factor: 1.000e+000 >>>>>> ** Total phase samples: 400000 >>>>>> ** Normal and Overlapping Allan deviation: >>>>>> >>>>>> 1 tau, 3.0127e-009 adev(n=399998), 3.0127e-009 oadev(n=399998) >>>>>> 2 tau, 1.5110e-009 adev(n=199998), 1.5119e-009 oadev(n=399996) >>>>>> 5 tau, 6.2107e-010 adev(n=79998), 6.1983e-010 oadev(n=399990) >>>>>> 10 tau, 3.1578e-010 adev(n=39998), 3.1549e-010 oadev(n=399980) >>>>>> 20 tau, 1.6531e-010 adev(n=19998), 1.6534e-010 oadev(n=399960) >>>>>> 50 tau, 7.2513e-011 adev(n=7998), 7.3531e-011 oadev(n=399900) >>>>>> 100 tau, 4.0029e-011 adev(n=3998), 4.0618e-011 oadev(n=399800) >>>>>> 200 tau, 2.1512e-011 adev(n=1998), 2.1633e-011 oadev(n=399600) >>>>>> 500 tau, 9.2193e-012 adev(n=798), 9.1630e-012 oadev(n=399000) >>>>>> 1000 tau, 4.9719e-012 adev(n=398), 4.7750e-012 oadev(n=398000) >>>>>> 2000 tau, 2.6742e-012 adev(n=198), 2.5214e-012 oadev(n=396000) >>>>>> 5000 tau, 1.0010e-012 adev(n=78), 1.1032e-012 oadev(n=390000) >>>>>> 10000 tau, 6.1333e-013 adev(n=38), 6.1039e-013 oadev(n=380000) >>>>>> 20000 tau, 3.8162e-013 adev(n=18), 3.2913e-013 oadev(n=360000) >>>>>> 50000 tau, 1.0228e-013 adev(n=6), 1.5074e-013 oadev(n=300000) >>>>>> 100000 tau, 5.8577e-014 adev(n=2), 6.7597e-014 oadev(n=200000) >>>>>> >>>>>> So far, so good. Now I delete every even line in the file which leaves >>>>>> me with 200000 lines of data (400000 lines in original gps.dat file). >>>>>> (awk 'and(NR, 1) == 0 {print}' <gps.dat >gps1.dat) >>>>>> >>>>>> C:\Documents and Settings\Steve Rooke\Desktop>adev1.exe 1 <gps1.dat >>>>>> >>>>>> ** Sampling period: 1 s >>>>>> >>>>>> >>> INCORRECT!! >>> sampling period is now 2s. >>> >>>>>> ** Phase data scale factor: 1.000e+000 >>>>>> ** Total phase samples: 200000 >>>>>> ** Normal and Overlapping Allan deviation: >>>>>> >>>>>> 1 tau, 3.0257e-009 adev(n=199998), 3.0257e-009 oadev(n=199998) >>>>>> 2 tau, 1.5373e-009 adev(n=99998), 1.5345e-009 oadev(n=199996) >>>>>> 5 tau, 6.3147e-010 adev(n=39998), 6.3057e-010 oadev(n=199990) >>>>>> 10 tau, 3.3140e-010 adev(n=19998), 3.3067e-010 oadev(n=199980) >>>>>> 20 tau, 1.7872e-010 adev(n=9998), 1.7810e-010 oadev(n=199960) >>>>>> 50 tau, 7.9428e-011 adev(n=3998), 8.1216e-011 oadev(n=199900) >>>>>> 100 tau, 4.2352e-011 adev(n=1998), 4.3265e-011 oadev(n=199800) >>>>>> 200 tau, 2.2001e-011 adev(n=998), 2.2593e-011 oadev(n=199600) >>>>>> 500 tau, 9.6853e-012 adev(n=398), 9.5441e-012 oadev(n=199000) >>>>>> 1000 tau, 5.0139e-012 adev(n=198), 5.0387e-012 oadev(n=198000) >>>>>> 2000 tau, 2.7994e-012 adev(n=98), 2.7090e-012 oadev(n=196000) >>>>>> 5000 tau, 1.4280e-012 adev(n=38), 1.2214e-012 oadev(n=190000) >>>>>> 10000 tau, 7.4881e-013 adev(n=18), 6.5814e-013 oadev(n=180000) >>>>>> 20000 tau, 7.6518e-013 adev(n=8), 3.7253e-013 oadev(n=160000) >>>>>> 50000 tau, 2.4698e-014 adev(n=2), 1.3539e-013 oadev(n=100000) >>>>>> >>>>>> Obviously we don't have enough data now for a measurement of 100000 >>>>>> tau but the results for the other tau are quite close, especially when >>>>>> there are sufficient data points. Now this is discontinuous data, >>>>>> exactly what I was trying to allude to. >>>>>> >>>>>> OK, so now I take only the top 200000 lines of the gps.dat file (head >>>>>> -200000 gps.dat >gps2.dat) >>>>>> >>>>>> C:\Documents and Settings\Steve Rooke\Desktop>adev1.exe 1 <gps2.dat >>>>>> >>>>>> ** Sampling period: 1 s >>>>>> ** Phase data scale factor: 1.000e+000 >>>>>> ** Total phase samples: 200000 >>>>>> ** Normal and Overlapping Allan deviation: >>>>>> >>>>>> 1 tau, 3.0411e-009 adev(n=199998), 3.0411e-009 oadev(n=199998) >>>>>> 2 tau, 1.4985e-009 adev(n=99998), 1.4999e-009 oadev(n=199996) >>>>>> 5 tau, 6.1964e-010 adev(n=39998), 6.2010e-010 oadev(n=199990) >>>>>> 10 tau, 3.1315e-010 adev(n=19998), 3.1339e-010 oadev(n=199980) >>>>>> 20 tau, 1.6499e-010 adev(n=9998), 1.6495e-010 oadev(n=199960) >>>>>> 50 tau, 7.1425e-011 adev(n=3998), 7.3416e-011 oadev(n=199900) >>>>>> 100 tau, 3.9940e-011 adev(n=1998), 4.0730e-011 oadev(n=199800) >>>>>> 200 tau, 2.1488e-011 adev(n=998), 2.1558e-011 oadev(n=199600) >>>>>> 500 tau, 8.4809e-012 adev(n=398), 9.0886e-012 oadev(n=199000) >>>>>> 1000 tau, 4.9223e-012 adev(n=198), 4.7104e-012 oadev(n=198000) >>>>>> 2000 tau, 2.4335e-012 adev(n=98), 2.4515e-012 oadev(n=196000) >>>>>> 5000 tau, 1.0308e-012 adev(n=38), 1.0861e-012 oadev(n=190000) >>>>>> 10000 tau, 5.9504e-013 adev(n=18), 6.1031e-013 oadev(n=180000) >>>>>> 20000 tau, 3.6277e-013 adev(n=8), 3.1994e-013 oadev(n=160000) >>>>>> 50000 tau, 1.0630e-013 adev(n=2), 1.6715e-013 oadev(n=100000) >>>>>> >>>>>> Is there any Linux tools for calculating adev as I'm having to run >>>>>> Windows in a VMware session? >>>>>> >>>>>> 73, >>>>>> Steve >>>>>> >>>>>> 2009/4/8 Tom Van Baak <t...@leapsecond.com>: >>>>>> >>>>>> >>>>>> >>>>>>> Steve, >>>>>>> >>>>>>> You've asked a couple of questions. Let me start with this. >>>>>>> >>>>>>> It is true that if one were only interested in the performance >>>>>>> of a pendulum (or quartz or atomic) clock for averaging times >>>>>>> of one day that all you would need is a series of time error >>>>>>> (aka phase) measurements made about the same time once >>>>>>> a day (doesn't have to be that exact). After one week, you'd >>>>>>> have 7 error measurements (=6 frequency =5 stability points) >>>>>>> and this is adequate to calculate the ADEV for tau 1 day. >>>>>>> This alone allows you to rank your clock among all the other >>>>>>> pendulum clocks out there. Note also you get time error and >>>>>>> rate error from these few data points too. >>>>>>> >>>>>>> As another example, suppose you have a nice HP 10811A >>>>>>> oscillator and want to measure its drift rate. In this case you >>>>>>> could spend just 100 seconds and measure its frequency >>>>>>> once a day, or even once every couple of days. Do this for >>>>>>> a month and you'd have several dozen points. If you plot >>>>>>> these frequency measurements you will likely see that they >>>>>>> approximately fall on a line; the slope of the is the frequency >>>>>>> drift rate of the 10811. The general shape of the points, or >>>>>>> the fit of the line is a rough indication of how consistent the >>>>>>> drift rate is or if it's increasing or decreasing. >>>>>>> >>>>>>> Neither of these examples require a lot of data. Both of these >>>>>>> are real-world examples. >>>>>>> >>>>>>> OK so far? >>>>>>> >>>>>>> /tvb >>>>>>> >>>>>>> >>>>>>> >>>>>>> _______________________________________________ >>>>>>> time-nuts mailing list -- time-nuts@febo.com >>>>>>> To unsubscribe, go to >>>>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>>>> and follow the instructions there. >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>> >>>>>> >>>>> _______________________________________________ >>>>> time-nuts mailing list -- time-nuts@febo.com >>>>> To unsubscribe, go to >>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>> and follow the instructions there. >>>>> >>>>> >>>>> >>>> >>>> >>>> >>> _______________________________________________ >>> time-nuts mailing list -- time-nuts@febo.com >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >>> >>> >> >> >> >> > > > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > -- Steve Rooke - ZL3TUV & G8KVD & JAKDTTNW Omnium finis imminet _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.