Re: [libreoffice-users] Filter algorithm question

On 02/22/2015 12:18 PM, office76#xt wrote:
> Hi,
>        This may sound like some ones homework but its really an algorithm
> question I have.
>
> Imagine you had a square plot of land. You could assign this to a grid and
> create a two dimensional graph with an X and Y-axis. Now imagine an inner
> square plot that's a wildlife sanctuary. Now you fly a camera drone over the
> outer plot and photograph all the pelicans nesting there. So your covering
> the outer plot and the inner sanctuary plot. Now you digitize the photo,
> enabling you to turn the pelicans into points on the X & Y graph. Then you
> take these X & Y points and either put them in a serial file or a
> spreadsheet.
>
> Now you want to filter the data, going through the X, Y pairs, and finding
> only those within the boundaries of the inner sanctuary plot. If you could
> do that you could count the pelicans, now represented by X, Y coordinates in
> your database, within the sanctuary.
>
> Say the outer plot is X = 20 and Y = 20. And the inner plot goes from 4 to 7
> on the X axis and from 6 to 9 on the Y axis.
>
> If you were reading your data into a BASIC program, you could use code like:
>
> If (X > = 4 AND X < = 7) AND (Y > = 6 AND Y < = 9) THEN Count = Count + 1
>
> This would look in the inner sanctuary boundaries, and if the data fell
> within its boundaries, you'd increment a counter to count the pelicans.
>
> This is great if the inner plot is rectangular. My question is, what if its
> irregular like a kidney shaped swimming pool? What would the filter code
> look like?
>
> I'm not asking for you to solve the problem here for me. I'm asking for any
> pointers to stuff on the web that may be applicable to this question. There
> must be a name for this problem but I really don't know what it is or where
> to start looking.
>
> Any ideas appreciated.
>
>
>
> --
> View this message in context: 
> http://nabble.documentfoundation.org/Filter-algorithm-question-tp4141022.html
> Sent from the Users mailing list archive at Nabble.com.
This should be problem that has occurred before, how to map and count 
instead a non-geometrical shape. I am not sure if something like Google 
Maps or Mapquest may have an API for something like this.

Depending on your programming skills, you might solve using a mapping 
protocol/API using data file as the input.

Jay

--
Jay Lozier
jslozier@gmail.com


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