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Topic: Interp1 Best Method?
Replies: 5   Last Post: Apr 17, 2013 6:07 PM

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Posts: 3
Registered: 4/17/13
Re: Interp1 Best Method?
Posted: Apr 17, 2013 5:11 PM
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dpb <> wrote in message <kkmr6h$l7v$>...
> On 4/17/2013 10:52 AM, XLT_Frank wrote:
> > dpb <> wrote in message <kkmd7e$ajg$>...
> >>
> >> I'd instead use the integer sampling rate as the time instead of float
> >> since you want an exact comparison and that's iffy w/ floating point
> >> and then use ISMEMBER or INTERSECT.

> ...
> > Thank you for the update. I will explore those. I am trying to figure
> > out what do about time. I was just informed that my date and time is not
> > being provided as some form of serial number in integer format. Instead
> > it is going to be a column with the date, likely in day of year, while
> > the time column is going to be hh:mm:ss.ssss. It should match the IRIG
> > MIL-1553 Chapter 10 format from the range commander's tools. I guess I
> > could request that they provide the RTC data, which is millisec since on
> > time and then just use the traditional date time for labeling.

> That'll work just fine w/ the DOY; ML DATENUM is smart enough to deal
> with it. Example,

> >> datestr(datenum(2013,0,33))
> ans =
> 02-Feb-2013

> >>
> Any field passed to datenum that exceeds proper range for the date/time
> will propagate to next higher field correctly accounting for day/month,
> leap year, etc., etc. IOW, you don't need anything special to deal with
> it in Matlab simply.
> Is the sampling process buffered so it is a precision and can just be
> assumed from the ordinal count and the sampling rate or is it a polling
> process where there is jitter and the sampled timestamp is significant?
> Generally sampled data is more like the former for such sampling rates
> and the RTC is just bookkeeping to keep track of what that particular
> record means in the larger context of the experiment, datalogger,
> whatever it is...
> --

I am not sure how to answer that. I am still coming up to speed on how the chapter 10 data is stored and the difference between the absolute and relative time and how the 1553 message is sampled.

I am now expecting my data to look like this (assuming a full date). I am going to be using mfcsvread. = '2013-03-01'
data1.time(1) = '18:42:55.496'
data1.sensorA(1) = -27

of course data2 would have a different time stamp and a different sensor. I would then use interp1 with the datenum serial values of data1.time and data2.time to ultimately create a data1.sensorB that is just an interpolated value. So would the serial value of datenum support the 1ms resolution of my data2.time values?

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