All,

 I want to do some analysis on several data sets onsisting of 32768 data
points per file.
 Each file consists of a signal value that has some average value, and
varies from the average value
 versus time.  From this information, one can determine the direction
and magnitude of each datapoint
 but subtracting the average from it (or adding, whichever is
appropriate).

 The next scenario is similar, but with a slight difference.  The data
from out DUT is going along
 just as it did in the scenario above for some period of time.  Then,
all of a sudden, there is a step
 function whering the data central value drops some arbitrary magnitude,
stays there for a while, then=20
 returns to the previous level and continues on as if nothing had
happened. =20
=20
 This step may happen once, it may happen several time, or it ma not
happen at all.

 With all of that said, here is the question...

 Is there a way to determine, using mathematical methods, if this step
dunction occured in a given file
 without actually graphing the file and physically looking at it?

 I have about 1000 files to check for this phenomenon, and I would like
to do some sort of mathematical
 analysis on it to fine files that have signs of this step function
happening rather than graphing each=20
 and every file, only to find most of them don't show the problem.

 What I want to do is do some dort of test on each data point and see if
here is a large step from one=20
 point to the next, and if so, how long (in sample periods) does it take
to get to the new steady value.
 Then test to see how many sample periods it stays at that new level.=20
And finally, how fast does it rise=20
 back to the previous steady level.

 I've tried the usual statistical functions, but I can't seem to get a
reliable indication.
 Does anyone have any idea?  If so, please enlighten me.

 =20
                                    2       4    =20
       .   . . .             ...    V       V       . . . .
1> ....  .      . . . . .  .    ....        . . ..        . . . . <5
        .                .          .       .
                                    .       .
                                    .   .   .
                                  3> . . . .
                                      .   .=20

 I have included ere a very primitive drawing of what I want to find.
 If this drawing comes through intact, you will see an average value,=20
 denoted by number 1 on the X axis. =20

 The at point 2, we see a sudden drop to a new average value at point 3.
 The signal stays at this level for a period of time (Varies between
occurances),
 and then goes back to the previous level at point 4, and stays at that
level for
 another period of time (like at point 5).

 The step may occur again in the same file one or more times, or it may
not
 happen again in that file at all.

 So if anyone has any ideas as to how to detect this mathematically, I'd
appreciate=20
 hearing how you propose to do it.  =20

 P.S.  This is not math homework, and I am not a student wanting help
with my homework.
       I am doing this as part of my employment.



 Thanks and Regards,

        Jim


--=20
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