Re: Object graphic 3d Scatterplot

[Ben Tupper <tupper(at)seadas.bigelow.org>]

Andrej Gapelyuk wrote:

> Hi all.
> I work with classification problem, and I would like to see how my data
> are distributed  s in 3d space with possibilities of rotation. It should
> be possible  to do with  the object graphic. I?d like to see data for
> different classes like small particles of different colors . The closest
> tip which I have found was ? How to Create 3D Scatterplot? from David
> website, but unfortunately it is a direct graphic. Any suggestion.
>
>

Hello,

The object graphics path is the right one for 3d scatter plots that you
want to rotate.  I have tried to perform the same kind of task using
datasets numbering in the thousands (of points.) Here's what I learned: be
advised that if you place you data into a IDLgrPlot object (using the
Zvalue and Use_Zvalue keywords) or IDLgrPolyLine, you can't make each point
a different color (to represent different classes) easily if you have a
large dataset.  For each type of object, the symbol cattributes are defined
by another object, IDLgrSymbol.  For each data point to have its own color,
you must define each point its own symbol object and then stuff them into
an object array.   That's ok for a small dataset; don't waste your time for
a large set.   I put in a request to allow the symbol object to accept an
arrays of attribute (like color, size, etc.) definitions rather than single
defintions.   You might think about placing a request in the queue also.

Ben


--
Ben Tupper

Bigelow Laboratory for Ocean Science
tupper@seadas.bigelow.org

pemaquidriver@tidewater.net