Re: Unbearably slow plotting (v6)David Bailey,http://www.dbaileyconsultancy.co.uk
- To: mathgroup at smc.vnet.net
- Subject: [mg79649] Re: Unbearably slow plotting (v6)David Bailey,http://www.dbaileyconsultancy.co.uk
- From: Bill Rowe <readnewsciv at sbcglobal.net>
- Date: Wed, 1 Aug 2007 04:58:33 -0400 (EDT)
On 7/30/07 at 6:39 AM, dave at Remove_Thisdbailey.co.uk (David Bailey) wrote: >Bill Rowe wrote: >>With 1E5 and 1E6 points, this results in a plot that is >>indistinguishable from a filled rectangle. That seems to be of very >>little use. So, while I might be a bit impatient waiting for >>Mathematica on my machine to plot 1E6 points, I don't see why I >>would want to do that in the first place. What I want from ListPlot >>is something to give me an idea of trends in my data. Given real >>limits on display resolution and size, plotting 1E6 points >>typically will not provide a useful plot regardless of how fast it >>plots. So why do this >The main reason people do this, is that they have experimental data >which they want to visualise without having to filter it in some way >to remove redundant data points. I certainly understand the need to visualize experimental data since that is one of the things I do most frequently with Mathematica. And I also understand the desire to do this as easily and efficiently as possible. But Mathematica is not a substitute for thinking about your data. If you ask Mathematica to plot a million points it will do so in whatever time is required. But such plots are almost never a good way to visualize data given typical sized displays and their resolution. In fact, one of the nice things about version 6 is it makes simple filtering such as taking every nth point very easy. For example, if I had 1E6 data points, I likely would initially plot every 100th point or every 1000th point to get a reasonable plot. As I am sure you are aware doing: ListPlot[datra[[;; ;;100]]] in version 6 will plot every 100th point. Yes, there is always a risk in using such simple filtering schemes important aspects of the data will be missed. But that same risk exists if all data points in such a large set are plotted. If there are only a few important points, plotting all of the points will almost certainly obscure the few important points. -- To reply via email subtract one hundred and four