[R-pkgs] Update of TeachingDemos package

[Greg Snow]

This is to announce that versio 2.0 of the TeachingDemos package is now
on CRAN (and hopefully soon to a mirror near you).

This is a major upgrade of the package, some of the improvements
include:

The package now uses an NAMESPACE so it is easier to load just the parts
that you need.

Some of the GUI demonstrations now use tkrplot so that the graph is in
the same window as the controls (there are still 'old' versions of these
functions available if you want the old functionality).  The rest of the
GUI demos will be updated to use tkrplot as well, and after R2.7 comes
out they all will be upgraded to use the themed widgets to give a more
uniform look with your OS.

Many of the examples sections of the help pages have replaced
"\dontrun{" with "if(interactive()){" so that they will be run by the
"example" function, but still not block in the automatic checking.  I
recommend running "example" with the argument "ask=FALSE", otherwise you
will need to hit enter 2-4 times each time a diolog pops up and every
time you update something in the dialog.

There are several new functions including:

tkexamp, a tool for creating interactive Tk based examples of what
options to functions do (mainly for plots, but one example shows a
non-plotting function).

dynIdentify and TkIdentify, tools that create a scatterplot with labels,
then allow you to drag the labels with the mouse to better locations.

col2grey, a tool to convert your colors to greyscale so you can get a
general feel of how they would look when printed non-color, or copied,
etc.

SensSpec.demo, a demonstration of how to compute positive and negative
predictive value from sensitivity, specificity, and prevelance using a
virtual population rather than Bayes Theorem and algebra.

TkApprox and TkSpline, GUI wrappers to the approxfun and splinfun
functions that graph your data, the predictions, and allow you to drag
reference lines on the plot to show the predicted values, differences,
and derivatives.

tkprogress, a utility to create and update a progress bar to show how
far through a loop or other iterative process you are.

A set of functions (see txtStart and etxtStart) that will create a plain
text transcript of your R session including both commands and output
(think glorified sink + history).  The 'etxt' versions add markup so
that the text file can be processed by the enscript program to create a
postscript file with some syntax coloring and inclusion of graphs.  The
postscript file can then be converted to pdf or other formats.


Hope others find this helpful,

-- 
Gregory (Greg) L. Snow Ph.D.
Statistical Data Center
Intermountain Healthcare
greg.snow at imail.org
(801) 408-8111