On Mon, Aug 05, 2002 at 02:23:07PM -0700, Ronnen Levinson wrote:> Hello. > > I have an XYY series that I would like to graph with matplot() or some > other single function that will do the trick. > The X in question is a vector of POSIXt values obtained from strptime(). >...> Is there a way for me to give plot() and/or > matplot() formatting instructions for POSIXt values? >Yup. In two steps... 1) plot, but without a labeled x-axis (x.stuff should have class "POSIXct"): matplot(x.stuff, y.stuff, xaxt="n") 2) you can now use axis.POSIXct() And a very nice function it is. You can tell it where to put the ticks (if you don't find the defaults appropriate), and what format to display the dates. Cheers Jason -- Indigo Industrial Controls Ltd. 64-21-343-545 jasont at indigoindustrial.co.nz -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
Hello.
I have an XYY series that I would like to graph with matplot() or some
other single function that will do the trick.
The X in question is a vector of POSIXt values obtained from strptime().
Is it possible to tell matplot() how to handle POSIXt x values?
I have examined the examples at
http://lark.cc.ukans.edu/~pauljohn/R/statsRus.html#5.22 , but would
prefer not have to overlay the results of multiple plot() calls.
Example:
a=strptime("06/01/2002 12:00:00","%m/%d/%Y %H:%M:%S")
x=seq(a,a+10*24*3600,length=3)
y=seq(1,4)
plot(x,y)
matplot(x,cbind(y,y))
I have also noticed that plot() seems to make judgement calls as to how
to present POSIXt values. For example,
a=strptime("06/01/2002 12:00:00","%m/%d/%Y %H:%M:%S")
x=seq(a,a+3*24*3600,length=3)
y=seq(1,4)
plot(x,y)
shows days of week. Is there a way for me to give plot() and/or
matplot() formatting instructions for POSIXt values?
Thanks,
Ronnen.
R1.5.1 on Windows 98
--
Ronnen Levinson, Ph.D. \/ RML27 at cornell.edu
scientist || http://ronnen.com
Lawrence Berkeley National Lab /\ fax 425.955.1992
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Dear list, I have done the ridge regression. But it seems the function lm.ridge does not return the variance for the estimators. Does anyone know how I can work out the variance for the estimators (my matrix has factors)? Thanks a lot? Huan -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._
You can also do ridge regression (penalized least squares) using the ols function in the Design library. This function provides standard errors but there is not a rich theory that provides complete comfort on their accuracy. Frank Harrell On Tue, 6 Aug 2002 10:51:55 +0100 Huan Huang <huang at stats.ox.ac.uk> wrote:> Dear list, > > I have done the ridge regression. But it seems the function lm.ridge does > not return the variance for the estimators. Does anyone know how I can work > out the variance for the estimators (my matrix has factors)? Thanks a lot? > > Huan > > -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- > r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html > Send "info", "help", or "[un]subscribe" > (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch > _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._-- Frank E Harrell Jr Prof. of Biostatistics & Statistics Div. of Biostatistics & Epidem. Dept. of Health Evaluation Sciences U. Virginia School of Medicine http://hesweb1.med.virginia.edu/biostat -.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.-.- r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html Send "info", "help", or "[un]subscribe" (in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch _._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._._