Re: Best performance using UnionSets

• To: "Ciccero A. W. Zandoná" <cicero@xxxxxxxxxx>
• Subject: Re: Best performance using UnionSets
• From: "From: Bill Hibbard <hibbard@xxxxxxxxxxxxxxxxx>" <billh@xxxxxxxxxxxxx>
• Date: Mon, 24 Sep 2001 17:41:27 -0500 (CDT)

Hi Cicero,

> I'm tring to plot a contour map inside a 2Ddisplay from a text file
> (more specific a .MIF file from the MapInfo software). My class is
> reading the polylines that are in the file and then creating
> Gridded2DSets for each one, then puting then on a Gridded2DSet array and
> then into a UnionSet.

I'm a little puzzled by 'contour map'. Is your map produced by
a contouring algorithm? Or is it an ordinary set of map outlines?

> Bill told me I should check how many GriddedSets I was creating but the
> number is about 400 and there are about 25000 points. I don't think this
> is so much.

I just printed internally from visad/data/mcidas/BaseMapAdapter.java
for the McIDAS map OUTLUSAM (U.S. map boundaries) and found that
it is a UnionSet of 857 Gridded2DSets with a total of 53706 points.
So about twice the size of your data in both counts. It displays
on my 500 MHz Dell under NT quite quickly.

> I'm using a IBM-PC 300Mhz and Ram:128Mb running Windows 98.
> 
> Please, somebody must have used maps on VisAD, and this can't be the way
> it is. I'm doing something wrong.

Since I am getting good performance on a data set twice the
size of yours, there probably is some problem. Have you tried
an OS other than Windows 98 (which isn't a real OS)?

You could try sending your code. There may be some error
we'll see.

Cheers, Bill

• References:
  • Best performance using UnionSets
    • From: Ciccero A. W. Zandoná