NOTICE: This version of the NSF Unidata web site (archive.unidata.ucar.edu) is no longer being updated.
Current content can be found at unidata.ucar.edu.
To learn about what's going on, see About the Archive Site.
NOTICE: This version of the NSF Unidata web site (archive.unidata.ucar.edu) is no longer being updated.
Current content can be found at unidata.ucar.edu.
To learn about what's going on, see About the Archive Site.
Hi > We also often notice that memory use is more than you'd > expect just by adding up the arrays. Especially when you > start generating displays. This is just Java memory > performance problems. Java3D version 1.2.1 should enable > us to improve this somewhat. I ran some basic tests, and after what I could see, the memory that is allocated as part of a method call is not released when it is finnished. At least not right away. When I repeated the a method call, the VM did not reuse the allocated memory from the first call, but rather allocated new resources for each call. Even when I forced garbage collection between each call. (System.gc() and System.runFinalization()). > Another approach would be for you to set your arrays = null after > you have constructed your Delaunay and Set classes, as a way to > conserve memory. This method will consume memory over time, when the garbage collector finally decides to go to work, but it does have a flaws. You allocate a new set of data before deleting the old one, meaning that you have twice as much memory consumed, and no control over when the first set is released. > There is no variable named "neighbor" in Delaunay. However, you > will note that the arrays in Delaunay are declared public, so you > can access them (of course, writing into them is a big safety > hole). My current method for extracting neighbors has complexity O(num_elms). For the dataset in question it takes about 30 seconds and 20Mb while computing, and returns an array of 2Mbs. Since I'm not very familiar with the implementation if Delaunay I was wondering if any of the public fields contained information that I could use to better the performance. I could not find in the documentation what is contained in the edges and walk arrays. I was hoping that some of this data could reduce my memory consumation. Gunnar
visad archives: