similar to: Partitioning Around Mediods then rpart to follow

Displaying 20 results from an estimated 8000 matches similar to: "Partitioning Around Mediods then rpart to follow"

2007 Apr 20
2
Partitioning around mediods (PAM)
Hi, I need some help understanding the output from PAM. When I look at the output it doesn't list the cluster number by the median vlaues on each of the variables (like it does with k-means) Instead I have the following: So I know for instance cluster 1 has a mean for variable1 of 33.33, however when I run PAM i get: variable 1 variable2 29 32 12 97 12
2010 Apr 11
0
plotting rpart objects, text.rpart, fancy option
I have created plots of rpart objects with the fancy option for text.rpart ("fancy" creates ellipses and rectangles and labels branches with splitting criteria). The ellipses and rectangles are supposed to "interrupt" the tree lines (as seen in Therneau and Atkinson 1997, page 48, Fig. 18, http://www.mayo.edu/hsr/techrpt/61.pdf), but they do not, even when I use Therneau and
2009 May 26
0
cross-validation in rpart
Dear R users, I know cross-validation does not work in rpart with user defined split functions. As Terry Therneau suggested, one can use the xpred.rpart function and then summarize the matrix of the predicted values into a single "goodness" value. I need only a confirmation: set for example xval=10, if I correctly understood a single column of the matrix obatined by xpred.rpart gives
2014 Aug 18
0
patch for rpart
On 08/14/2014 05:00 AM, r-devel-request at r-project.org wrote: > Dear list > > > For my work, it would be helpful if rpart worked seamlessly with an > empty model: > > library(rpart); rpart(formula=y~0, data=data.frame(y=factor(1:10))) > > Currently, an unrelated error (originating from na.rpart) is thrown. > > At some point in the near future, I'd like to
2006 Sep 25
2
rpart
Dear r-help-list: If I use the rpart method like cfit<-rpart(y~.,data=data,...), what kind of tree is stored in cfit? Is it right that this tree is not pruned at all, that it is the full tree? If so, it's up to me to choose a subtree by using the printcp method. In the technical report from Atkinson and Therneau "An Introduction to recursive partitioning using the rpart
2001 Jul 26
0
tree and rpart
There have been various messages about packages tree and rpart whilst I have been travelling, and I have now prepared updates. tree ==== Tree is one of the oldest packages on CRAN (Feb 2000 apart from adding the maintainer field), and I had been hoping that it would fade away in favour of rpart. 1) sys.parent needed to be replaced by parent.frame in all but the most recent R (post 1.3.0).
2002 Aug 28
0
user defined function in rpart
Hi, I am trying to use the rpart library with my own set of functions on a survival object. I get an immeadiate segmentation fault when i try calling rpart with my list of functions. I get the same problem with the logrank example from Therneau,s S-rpart library though their anova example works. Should I report this as a bug, as even if my functions are structured improperly, that should lead to
2009 May 14
0
Rpart - user defined split functions
Dear all, I'm writing my own method to be used in Rpart by defining the list of functions named init, split and eval. I'm following the example given in the file 'tests/usersplits.R' in the sources. By now I'm able to define the split function (and it works correctly in the tree construction) while I have some problems with the init and the eval function. The task I'm
2011 Jan 11
0
Some questions concerning survival tree analysis using the rpart module
All the documentation that I have on survival splitting is found in the technical report you mention. However, there is both a short form and a long form of this on our web site, did you get the larger one (52 pages)? I admit it is not a lot. There are no other split algorithms implimented for survival data. It would be possible to add your own. Attached is a slightly updated version of the
2009 Aug 30
1
Complexity parameter in rpart
Hi all, I'm currently using the 'rpart' function to run some regression analysis and I am at the point where I wish to prune my overfitted trees. Having read the documentation I understand that to do this requires the use of the complexity parameter. My question is how to go about choosing the correct complexity parameter for my tree? In some places
2008 Feb 14
0
User defined split function in Rpart
The question is about the direction vector in rpart. There are (at least) two preferred ways to lay out a tree, wrt the question of which obs are sent left and which right. 1. Send the smaller y values to the left. In the final tree, there will be a graphical ordering with smaller y's to the left and larger ones to the right. One has a "left bad, right good"
2004 Jan 07
0
rpart question on loss matrix
Hello again I've looked through ?rpart, Atkinson & Therneau (1997), Chap 10 of Venables and Ripley, Breman et al., and the r hgelp archives but haven't seen the answer to these two questions 1) How does rpart deal with asymmetric loss matrices? Breiman et al. suggest some possibilities, but, of course, do not say how rpart does it. 2) In the loss matrix, which direction (column or
2011 Mar 07
0
Re transaction list transformation to use rpart.
> However the as.data.frame(a) transforms the matrix into a numeric > data.frame so when I implement the rpart algorithm it automatically > returns a regression classification tree. Look at help(rpart). The program uses the type of the y variable to GUESS at what you want for the "method" argument. It often guesses wrong. Simply add method="class" as an
2001 Nov 12
0
Additional Documentation for rpart?
Dear r-help, I am looking for additional documentation on the "adj" column in rpart's splits matrix. The help says: adj gives the adjusted concordance for surrogate splits I am looking info about "adjusted concordance". I cannot find this phrase in either Therneau & Atkinson original RPART documentation or the CART book. This question came up in the
2011 Mar 06
1
transaction list transformation to use rpart.
So there are a couple parts to this question. I am trying to implement the rpart/random forest algorithms on a transaction lists. That is to say i am trying to train models in order to deduce what are the most predictive transactions within a customers history in order apply this model to future test data and identify accounting irregularities(ie. this account had x and y so they should have also
2011 Jun 21
0
How does rpart computes "improve" for split="information"?? (which seems to be different then the "gini" case)
Hello dear R-help members, I would appreciate any help in understanding how the rpart function computes the "improve" (which is given in fit$split) when using the split='information' parameter. Thanks to Professor Atkinson help, I was able to find how this is done in the case that split='gini'. By following the explanation here:
2002 Jan 07
1
is then an equivalent of partition.tree for rpart?
partition.tree plots in 2d the partition of a classification tree produced by the function tree (assuming the data frame from which it was computed has two continuous predictors). I get an error when I feed a tree produced by rpart to partition.tree (since trees produced by rpart are superclasses of those produced by tree). Is there an equivalent of partition.tree for objects of class rpart?
2009 Jan 09
2
rpart with interval censored data crashes R
Hi Everyone, This example code results in R 'crashing'; that is the R application closes with no warnings or error messages. #----------------------- myD <- read.table(stdin(), header=TRUE, nrows=20) Broth Salt pH Temp N Y Growth 1 310 9.0 2.92 10 90.0 NA 0 2 615 6.0 7.82 30 1.0 2 1 3 217 2.0 7.34 10 7.0 8
2010 Oct 18
0
specifying lme function with a priori hypothesis concerning between-group variation in slopes
I want to specify a 2-level mixed model using the lme function in order to test an a priori hypothesis about the between-group values of the slopes but don't know how to do this . Here is the problem. Consider first the case of a single group. The model is: Y_i= a +bX_i + error where I indexes the different values of X and Y in this group . The a priori hypothesis of the slope is: b=K.
2009 Jun 09
3
rpart - the xval argument in rpart.control and in xpred.rpart
Dear R users, I'm working with the rpart package and want to evaluate the performance of user defined split functions. I have some problems in understanding the meaning of the xval argument in the two functions rpart.control and xpred.rpart. In the former it is defined as the number of cross-validations while in the latter it is defined as the number of cross-validation groups. If I am