Viewing the dynamical systems and other interactive content on this site

This site contains interactive graphical content and like many such sites is more readable using a browser plug-in.  This content allows the site to re-compute the calculations behind a figure as you change the position of a lever, button, or knob, for example. Below are some details. We start with the basics in a nutshell to help new readers get started with our site:


(1) MAKE SURE YOU HAVE A CDF-CAPABLE BROWSER (see the list and download links below)

(2) MAKE SURE YOU HAVE EITHER OF TWO WOLFRAM PROGRAMS ON YOUR COMPUTER: the free CDFPlayer or Mathematica. (Download CDFPlayer at this page on the company’s site or read more about CDF technology at this second page. You will want the free CDFPlayer program partly because it includes “browser plug-ins” for some web browsers, as explained below.)

Some Wolfram CDF (computable document format) applets are embedded on individual posts and pages. Also, these CDFs are available in separate files with the .cdf extension, which can be downloaded on content pages or at the site’s standalone CDF archive page. In the case of the embedded content, the CDF runs on a server; standalone CDFs run on the your computer with the help of the CDFPlayer program.

The interactive CDF graphics contain levers and other controls that enable you to move things around by trying different numbers for the underlying parameters or making other changes to the assumptions used to perform calculations. The CDF content should appear within a reasonable amount of time after a page is opened, provided you are using an appropriate browser and browser plug-in. There is often a delay of a few seconds, during which you will see a spinning CDF logo. The latter is a good sign that you have the software (browser and plug-in). Two things can indicate something has gone wrong with this process: you either see no moving graphics or the spinning logo is never replaced by the CDF content.  You may want to try reloading if the CDF fails to appear.

Some compatible browsers:

I have found that the following browsers are currently good for viewing the interactive content in this site as of this date:

Internet Explorer 11 (download here)

Apple Safari 5.1.7 (download here)

Mozilla Firefox 47.0 (download here)

At the moment, among these three, Internet Explorer 11 seems to work best to view the embedded CDFs on this site with my computer and more than one different wi-fi connection.  Apple Safari seemed to be second best in my very informal check for site usability.

I was using a laptop with the Windows 10 operating system. Many viewers will doubtless have varying experiences using different platforms.  The following is a list of platforms compatible with the CDF player:

PLATFORMS SUPPORTED BY Wolfram CDFPlayer and Mathematica (source link):

Windows 10, 8, 7, Vista

Mac OS X 10.7+

Linux (desktop functionality only; no browser plug-in)

In recent statements, Wolfram sees its industry as moving away from plug-in technology and anticipates that its users will move toward its Wolfram Cloud for posting online content. We hope that one way or another this site will be able to keep provide its online content available to you via your computer or device as technological change marches onward.

Finally, a list of some actions to try once you have things up and running:


(1) on 3D graphics, grab the axes or box and rotate them

(2) if the CDF appears not to be working, reload the page

(3) click on the + symbol near a lever. You should see additional options appear.



A Q&A about CDFs at the Wolfram website states the following about this warning message:

“When I open a CDF, I see a warning about dynamic content. What does that mean?
Files containing interactive content can automatically evaluate code without any additional action by the user, aside from opening the file.
“Certain directories, including the desktop and downloads directories, are “untrusted” by default, so opening a CDF that is stored there (or in a subdirectory of the desktop) will trigger the warning. You can click the button in the warning to enable dynamic content. For more information, see the Notebook Security tutorial.”


I welcome feedback and comments on these issues, either below, or by email the following address: mail at greghannsgen dot org.

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