Displaying 20 results from an estimated 700 matches similar to: "Help with Projection Pursuit, ppr()."
2008 Oct 28
1
Source code for ppr (Projection Pursuit Regression)
Dear R users,
I am looking for the source code of the implementation of ppr (Projection
Pursuit Regression) in R.
It will be great if citations of the source papers on which the
implementation is based, are also provided.
Thank you,
Arvind Iyer,
Grad student, Deptt. of Biomedical Engineering
Viterbi School of Engineering
University of Southern California, Los Angeles
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2000 Nov 22
3
Confidence interval
I have this question I hope you can answer. First, lets see this simple example, using the Student's t-test:
> test<-t.test(miTest.data, mu=0.5, conf.level=0.90 )
> test
One Sample t-test
data: miTest.data
t = 0.5222, df = 9, p-value = 0.6141
alternative hypothesis: true mean is not equal to 5
90 percent confidence interval:
3.744928 7.255072
sample estimates:
mean
2010 Jul 29
1
Crash report: projection pursuit & predict
Folks,
The projection pursuit regression function in the base R seems to crash when the optimization level is set to zero, i.e. the initial ridge terms are accepted without refitting. I encountered this problem in an out-of-sample prediction exercise using predict. But further investigation suggests the issue is with the ppr fit and predict just sppeds up the crash. The other optlevels seem to be
2001 Jun 08
1
:predict.ppr
Hi all,
I am doing a projection pursuit regression using the ppr() function from
modreg.
I would also like to use predict.ppr(). However, I cannot find any
information about it in the help files. There is a link to predict.ppr
in the index for modreg, but that link is to the help for ppr().
Has predict.ppr() not been implemented?
If not, does anyone have a suggestion as to how to implement
2001 Feb 12
2
supsmu vs. ppr
I used the supersmoother function in the modreg package as follows:
super <- supsmu(ilogemp,award)
Then I decided that I might want additional explanatory variables (other
than ilogemp) in my model. The ppr function in modreg seemed a logical
extension of supsmu from univariate to multidimensional explanatory
variables. As a "check" I ran the following:
pprest <-
2006 Jun 28
1
Reporting ppr fits and using them externally.
The pursuit projection packages ppr is an excellent contribution to
R. It is great for one-to-three ridge fits,
often somewhat intuitive, and for multi-ridge fits, where it at least
describes a lot of variance.
Like many folk, I need to report the fits obtained from ppr to the
greater, outside, non-R
world. It is fairly obvious how to use the terms alpha and beta to
report on
2001 Jun 06
1
ppr, number of terms, and data ordering
Dear R listers --
I have several questions about using the ppr command in the modreg module.
I discovered -- quite by accident -- that if I re-order the data, I obtain different
results. The output below shows what I mean. I have two datasets (dataset1 and dataset2)
that are identical (tested using proc compare in SAS) except for the fact that the records
are in different order. Below I have
2005 Jul 11
1
Projection Pursuit
Hello,
Just a quick question about ppr in library modreg.
I have looked at Ripley and Venables 2002 and it says that projection
pursuit works "by projecting X in M carefully chosen directions"
I want to know how it choses the directions? I presume it moves around the
high-dimensional space of unit vectors finding ones that separate the
response variables, but how.
I looked at the
2005 Oct 27
0
Fw: Example where PPR crashes
Dear all,
I have been doing tests using SVM, random forests and PPR. The data is from a data stream (that is, the data for training and for test is always increasing / changing). With SVM and random forests everything is ok, but with ppr there are situations where it crashes. For the examples I have used I noticed that if one of the variables has just one value (it can happen), it crashes for
2001 Mar 20
3
Newbie question about by() -- update
Sorry about the lack of detail. I am running R v.1.2.2. I can recast my
question
(which I think I have partially answered) more succinctly as follows:
1. This seems to work (note that group takes values 1,2,3,4, or 5):
my.newfun <- function(x) myfile <- lm(award ~ ilogemp + ilogage, x)
test.by <- by(wintemp, as.factor(wintemp$group), my.newfun)
2. This does not work (leaving aside
1998 Jun 24
0
R-beta: Packages: KernSmooth logspline ppr rpart tree
The following are now on CRAN:
KernSmooth: version 2.2 of the code for Wand & Jones book on kernel smoothing.
logspline: spline fits to log denisites, with automatic choice of smoothing.
ppr: projection pursuit regression.
rpart: recursive partitioning (CART-like)
VR: Venables & Ripley libraries 5.3pl021 for 0.62.1
and in the devel section
tree: a clone
1998 Jun 24
0
R-beta: Packages: KernSmooth logspline ppr rpart tree
The following are now on CRAN:
KernSmooth: version 2.2 of the code for Wand & Jones book on kernel smoothing.
logspline: spline fits to log denisites, with automatic choice of smoothing.
ppr: projection pursuit regression.
rpart: recursive partitioning (CART-like)
VR: Venables & Ripley libraries 5.3pl021 for 0.62.1
and in the devel section
tree: a clone
2011 Feb 16
0
Constraints in projection pursuit regression
Hi,
I am solving a projection pursuit regression problem, of the
form y = \sum_i f_i (a_i^T x), where a_i are unknown directions, while
f_i are unknown univariate link functions. The following is known about
each f_i:
1. f_i (0) = 0 (that is, each f_i passes through the origin)
2. f_i is monotonic.
Is there a way to ensure that the function ppr() in R produces solutions that respect the
2007 Feb 08
1
supsmu(periodic=TRUE) can crash R by reading before start of array (PR#9502)
supsmu(periodic=TRUE) can crash R by reading before start of array.
To reproduce:
set.seed(1)
xx <- runif(29000)
yy <- rnorm(29000)
span <- 0.49
i <- 1
while(i < 200){
cat(i,"\n")
int <- supsmu(xx,yy,periodic=T,span=span)
i <-i+1
}
results in:
1
2
3
4
5
6
7
8
9
Program received signal SIGSEGV,
2009 Feb 10
0
PPR crash (PR#13517)
Full_Name: Hugh Miller
Version: 2.8.1
OS: XP
Submission from: (NULL) (128.250.24.101)
Hi there,
I've been looking at approaches that use the projection pursuit regression
function fairly (ppr) heavily, and have discovered that it crashes my R system
on occasion. It only happens with the inputs are pathological in some way I
don't understand. I have pasted such an example below.
Any
2001 Mar 28
4
efficiency and "forcing" questions
Dear R listers --
The program below does the following tasks:
1. It creates a file (wintemp4) that is a subset of alldata4 consisting of
"winner" records in 50 industry groups (about 5400 obs);
2. It defines a function (myppr1) that runs the ppr function in modreg
once to generate goodness of fit (sum of squared errors) measures by number
of terms included in model and then reruns
2001 Mar 16
1
Newbie question about by()
Dear R list:
I want to make separate estimates for each level of the variable "group."
After consulting many sources I am stumped as to why the following does not work:
> wintemp <- subset(alltemp, winner==1)
> my.ppr <- function(x)
+ {
+ if(nrow(x) >= 50) {
+ pprfile <- ppr(award~ilogemp, data=x,nterms=5,max.terms=10,optlevel=3)
+ summary(pprfile)
+
2013 Apr 23
2
Metaflac UTF-8 fixes
Hopefully the last patch from me to UTF-8 issues.
Metaflac can now print all console supported characters from tags on the
screen. It also fixes metaflac to be able to import its own exports back
without non-ascii characters getting mutilated. And --no-utf8-convert
now works properly with import and export commands.
I updated my Windows binary archive with these changes for any
interested
2005 Sep 06
2
Predicting responses using ace
Hello everybody,
I'm a new user of R and I'm working right now with the ACE function
from the acepack library. I Have a question: Is there a way to predict
new responses using ACE? What I mean is doing something similar to the
following code that uses PPR (Projection Pursuit Regression):
library(MASS)
x <- runif(20, 0, 1)
xnew <- runif(2000, 0, 1)
y <- sin(x)
a <- ppr(x, y,
1999 Jun 28
1
R-0.64.1 make problem: Solaris 2.4
Greetings,
I'm attempting to install R-0.64.1 on a Sun Sparc 20 running Solaris 2.4 with
gcc-2.7.2.2, g77-0.5.20 and Gnu make 3.76-1.
On several occasions, the make process aborted when trying to build the shared object
file for the modreg package (its first attempt at such a beast). In all attempts, the error
message is as follows:
../../../../bin/R SHLIB -o modreg.so bsplvd.o bvalue.o