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Topic: An idea to implement.
Replies: 3   Last Post: Mar 16, 2013 12:03 AM

 Messages: [ Previous | Next ]
 Derek Goring Posts: 3,663 Registered: 12/7/04
Re: An idea to implement.
Posted: Mar 14, 2013 3:06 PM

On Friday, March 15, 2013 4:32:08 AM UTC+13, Roy wrote:
> dpb <none@non.net> wrote in message <khsmmg\$vsu\$1@speranza.aioe.org>...
>

> > On 3/14/2013 8:43 AM, Roy wrote:
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> > ...
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> >
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> > > Guys sorry for not being so precise . I actually want to calculate the
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> > > mean and standard deviation.Here is a better way of saying it
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> > >
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> > > Take a scenario of a room with several anchors(nodes) inside the room. I
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> > > have all the measured data of those anchors for example Server
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> > > time,TOA,Anchor ID, Anchor channel,Anchor number,blink ID,Source
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> > > ID,Source channel,Time,agc(values).With the help of these available data
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> > > how do I find the mean and standard deviation of this scenario.For more
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> > > understanding,
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> > > Assume a matrix form, Anchor 1 2 3
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> > > 1 m,sd m,sd m,sd
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> > > 2 m,sd m,sd m,sd
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> > >
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> > > 3 m,sd m,sd m,sd
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> > > In this scenario you can see the anchors as 1x1 , 1x2 ..... 3x3 .
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> >
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> > I see no such thing...I see what appears to be a column vector of
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> > postions and another array that I have no idea what it is supposed to
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> > represent -- is this a format of a data file, some mapping into a 2D
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> > geometry of locations, what? I presume 'm,sd' is supposed to represent
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> > a mean and std dev but if you already have them, what's to compute or is
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> > it a file-parsing problem, I can't tell...
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> >
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> >
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> > > So with in the Anchor 1 in row vector and anchor 1 in column vector I
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> > > have to find the mean and standard deviation until 3x3.
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> >
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> > I have no idea what the above means.
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> >
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> > Start w/ the actual data format you have to work from and an example
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> > (preferably short) of the data itself...
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> >
>
> > --
>
> actually the matrix i represented was more like a geometric location . I just want you to assume that your are standing in a room with 4 anchors on the corners of the room. you now know the anchor ID's , the blink rate , TOA(time of arrival) ,the channel to which the blinks are received and transmitted, the AGC value etc all the info(that's what I meant as measured data) you need, now you have to find the mean(M) and standard deviation(SD) and also the pathloss(PL) exponent of this scenario.How do write (in matlab) with the given set of values to find the M,SD,PL.
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>
>

> > > So with in the Anchor 1 in row vector and anchor 1 in column vector I
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> > > have to find the mean and standard deviation until 3x3.
>
>
>
> This I actually meant like consider the four anchors in corners as A,B,C,D. So you will find the mean,standard deviation and pathloss exponent between A and B anchors , A and C, A and D likewise.
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>
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> My question is how do I write the code with this available data. I mean how should this be structured like ?
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>
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> Now, did you understand what I mean ?

It's still unclear to me.
In your matrix, you show locations as indexes (which we all understand), but in the above you refer to A, B, C, and D. Where did the letters come from? Why not refer to the locations as M(1,2), M(2,1), etc?
You obviously have a meaning for anchor which differs from my maritime understanding of the meaning.
What are AGC and pathloss exponent? Your jargon is gibberish to us.

To get either a mean or standard deviation in Matlab, you do this:
mean(y) or std(y)
where y is a vector of data, in other words a sequence of numerical values, e.g.,
y=[10 20 50 60 20 10];
ybar=mean(y);
ysd=std(y);

You need to couch your problem in these terms.

But maybe this is not what you are looking for, and what you mean is not standard deviation, but covariance or correlation.
help cov
help corrcoef

Date Subject Author
3/14/13 Derek Goring
3/16/13 Marc