On 22 Mag, 08:32, "Skybuck Flying" <BloodySh...@[EMAIL PROTECTED]
> wrote:
> What do you want to plot on the x and y-axis ?
>
> For example:
>
> Y-axis: Value
> /|\
> =A0|
> =A0|
> =A0|
> =A0|
> =A0|
> =A0|
> =A0|
> =A0.--------------------> X-Axis: Time.
> /|\
> Base Time
>
> Simply store the time in the list as well together with the value.
>
> Then use a variable called "base time"
>
> The base time always starts at the origin.
>
> Now to know where to "plot" the measurements simply do something like
this=
:
>
> Y =3D Measurement.Value;
> X =3D Measurement.Time - BaseTime;
>
> Plot( X, Y );
>
> This will draw old measurements on the left
> This will draw new measurements on the right.
>
> Then have a timer update the base time... like a few times per second or
s=
o.
>
> This will make the chart "walk" to the left to display new values.
>
> Add new measurements to the back of the list.
> Remove old measurement from the front of the list.
>
> To draw/plot the list:
>
> Walk the list from first to last element.
>
> (This is opposite from your drawings ;) maybe you want the chart to walk
t=
o
> the right ? ;))
>
> Hope this helps.
>
> Bye,
> =A0 Skybuck.
On 22 Mag, 08:32, "Skybuck Flying" <BloodySh...@[EMAIL PROTECTED]
> wrote:
> What do you want to plot on the x and y-axis ?
=2E..
>
> Now to know where to "plot" the measurements simply do something like
this=
:
>
> Y =3D Measurement.Value;
> X =3D Measurement.Time - BaseTime;
>
> Plot( X, Y );
>
> This will draw old measurements on the left
> This will draw new measurements on the right.
>
> Then have a timer update the base time... like a few times per second or
s=
o.
>
> This will make the chart "walk" to the left to display new values.
>
> Add new measurements to the back of the list.
> Remove old measurement from the front of the list.
>
> To draw/plot the list:
>
> Walk the list from first to last element.
>
> (This is opposite from your drawings ;) maybe you want the chart to walk
t=
o
> the right ? ;))
>
> Hope this helps.
>
> Bye,
> Skybuck.
Hi Skybuck,
I am afrais I did not explain well. I try again.
The chart is has:
X: Time
Y: Represented Values
The new values are represented on the right (most recent time).
The list I use is storing an object: (Time, Value)
I insert the new value (most recent time) at the beginning of the
list
[this is immaterial I could do the opposite as well]
The core of the problem is that the base time or initial time is
*not* updated but remain fixed.
So the chart has to *shrink*.
In other words, my 500 values initially represent a small timespan,
but as time goes by
the may represent hours and days and months.
That's why I need a "resampled" version of the time series. And the
resampling must
be done continuosly, ad the new data arrives.
So the problem in not in the chart contruction (which I know how to
do) but in the strategy to sample the data.
My problem is that I want to maintain the "shape" of the whole series.
So the shrinked
chart has to "represent" ALL the valued observed up to a given time.
The starting time remains fixed and it is located in the origin of the
Cartesian coordinates.
The chart walks only towards the future, the origin must represent
always the same time (start time): it "shrinks".
Is this explanation understandable?
-Pam
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