Displaying 20 results from an estimated 10000 matches similar to: "how to use node info generated by rpart in mars?"
2010 Oct 12
6
Rpart query
Hi,
Being a novice this is my first usage of R.
I am trying to use rpart for building a decision tree in R. And I have the
following dataframe
Outlook Temp Humidity Windy Class
Sunny 75 70 Yes Play
Sunny 80 90 Yes Don't Play
Sunny 85 85 No Don't Play
Sunny 72 95 No Don't Play
Sunny 69 70 No Play
Overcast 72 90 Yes Play
Overcast 83 78 No Play
Overcast 64 65 Yes Play
Overcast 81 75
2004 Jan 07
1
Questions on RandomForest
Hi, erveryone,
I show much thanks to Andy and Matthew on former questions. I now sample
only a small segment of a image can segment the image into several classes
by RandomForest successfully. Now I have some confusion on it:
1. What is the internal component classifier in RandomForest? Are they the
CART implemented in the rpart package?
2. I use training samples to predict new samples. But
2011 Apr 08
4
Rpart decision tree
Dear useRs:
I try to plot an rpart object but cannot get a nice tree structure plot. I
am using plot.rpart and text.rpart (please see below) but the branches that
connect the nodes overlap the text in the ellipses and rectangles. Is there
a way to get a clean nice tree plot (as in the Rpart Mayo report)? I work
under Windows and use R2.11.1 with rpart version 3.1-46.
Thank you.
Tudor
...
2008 Jan 29
2
rpart error when constructing a classification tree
I am trying to make a decision tree using rpart. The function runs very
quickly considering the size of the data (1742, 163). When I call the
summary command I get this:
> summary(bookings.cart)
Call:
rpart(formula = totalRev ~ ., data = bookings, method = "class")
n=1741 (1 observation deleted due to missingness)
CP nsplit rel error
1 0 0 1
Error in yval[, 1] :
2011 Jan 24
1
How to measure/rank “variable importance” when using rpart?
Hello all,
When building a CART model (specifically classification tree) using rpart,
it is sometimes interesting to know what is the importance of the various
variables introduced to the model.
Thus, my question is: *What common measures exists for ranking/measuring
variable importance of participating variables in a CART model? And how can
this be computed using R (for example, when using the
2001 Jul 12
2
rpart puzzle
I've been using the package rpart with R 1.3.0 for Windows to produce
simple classification trees for some measurement data from paleontological
specimens. Both the rpart documentation and the output confirm that the
program produces splits on continuous data that leave "holes" in the
data. It is probably of little practical importance, but is there a reason
why the binary
2009 May 12
1
questions on rpart (tree changes when rearrange the order of covariates?!)
Greetings,
I am using rpart for classification with "class" method. The test data is
the Indian diabetes data from package mlbench.
I fitted a classification tree firstly using the original data, and then
exchanged the order of Body mass and Plasma glucose which are the
strongest/important variables in the growing phase. The second tree is a
little different from the first one. The
2009 May 22
1
bug in rpart?
Greetings,
I checked the Indian diabetes data again and get one tree for the data with
reordered columns and another tree for the original data. I compared these
two trees, the split points for these two trees are exactly the same but the
fitted classes are not the same for some cases. And the misclassification
errors are different too. I know how CART deal with ties --- even we are
using the
2004 Jun 04
1
rpart
Hello everyone,
I'm a newbie to R and to CART so I hope my questions don't seem too stupid.
1.)
My first question concerns the rpart() method. Which method does rpart use in
order to get the best split - entropy impurity, Bayes error (min. error) or Gini
index? Is there a way to make it use the entropy impurity?
The second and third question concern the output of the printcp() function.
2011 Jul 29
1
help with predict.rpart
? data=read.table("http://statcourse.com/research/boston.csv", ,
sep=",", header = TRUE)
? library(rpart)
? fit=rpart (MV~ CRIM+ZN+INDUS+CHAS+NOX+RM+AGE+DIS+RAD+TAX+
PT+B+LSTAT)
predict(fit,data[4,])
plot only reveals part of the tree in contrast to the results on obtains
with CART or C5
-------- Original Message --------
Subject: Re: [R] help with rpart
From: Sarah
2011 Jan 24
1
How to measure/rank ?variable importance when using rpart?
--- included message ----
Thus, my question is: *What common measures exists for ranking/measuring
variable importance of participating variables in a CART model? And how
can
this be computed using R (for example, when using the rpart package)*
---end ----
Consider the following printout from rpart
summary(rpart(time ~ age + ph.ecog + pat.karno, data=lung))
Node number 1: 228 observations,
2012 Mar 04
1
rpart package, text function, and round of class counts
I run the following code:
library(rpart)
data(kyphosis)
fit <- rpart(Kyphosis ~ ., data=kyphosis)
plot(fit)
text(fit, use.n=TRUE)
The text labels represent the count of each class at the leaf node.
Unfortunately, the numbers are rounded and in scientific notation rather
than the exact number of examples sorted by that node in each class.
The plot is supposed to look like
2010 May 03
1
rpart, cross-validation errors question
I ran this code (several times) from the Quick-R web page (
http://www.statmethods.net/advstats/cart.html) but my cross-validation
errors increase instead of decrease (same thing happens with an unrelated
data set).
Why does this happen?
Am I doing something wrong?
# Classification Tree with rpart
library(rpart)
# grow tree
fit <- rpart(Kyphosis ~ Age + Number + Start,
2007 Mar 30
2
Minimum valid number of observations for rpart
Hi,
I wonder if anyone knows a study dealing with the minimum valid number of
observations when using CART?.
On top of that, when using RandomForest, is it possible to obtained a
interpretable tree model as the graphical output of the analysis, just
like in "rpart"?
Thanks a lot in advance
Javier Lozano
Universidad de Le?n
Spain
2010 Dec 14
1
rpart - how to estimate the “meaningful” predictors for an outcome (in classification trees)
Hi dear R-help memebers,
When building a CART model (specifically classification tree) using rpart,
it is sometimes obvious that there are variables (X's) that are meaningful
for predicting some of the outcome (y) variables - while other predictors
are relevant for other outcome variables (y's only).
*How can it be estimated, which explanatory variable is "used" for which of
2011 Sep 08
1
"rpart" or "tree" function issue
I am trying to create a classification tree using either tree or rpart
functions but when it comes to plotting the results the formatting I get is
different than what I see in all the tutorials (like
http://www.youtube.com/watch?v=9XNhqO1bu0A or
http://www.youtube.com/watch?v=m3mLNpeke0I&feature=related or
http://www.statmethods.net/advstats/cart.html "tree for kyphosis"). I am
2001 Aug 02
1
Missing value in Rpart
Hi, all
Our understanding of how classification trees in Rpart treat missing is
that if the variable is ordinal(continous), Rpart, by default, imputes a
value for missing. How do we do the classification tree and tell Rpart not
to impute. That is, what command is used to turn off the imputation.
Also, if we do get true missing, how does classification tree analysis in
Rpart treat missing when
2010 Mar 07
1
Is there an equivalence of lm's “anova” for an rpart object ?
Simple example:
# Classification Tree with rpart
library(rpart)
# grow tree
fit <- rpart(Kyphosis ~ Age + Number + Start,
method="class", data=kyphosis)
Now I would like to know how can I measure the "importance" of each of my
three explanatory variables (Age, Number, Start) in the model?
If this was a regression model, I could have looked at p values from the
2009 Jun 19
4
Recursive partitioning algorithms in R vs. alia
Dear R-helpers,
I had a conversation with a guy working in a "business intelligence"
department at a major Spanish bank. They rely on recursive partitioning
methods to rank customers according to certain criteria.
They use both SAS EM and Salford Systems' CART. I have used package R
part in the past, but I could not provide any kind of feature comparison
or the like as I have no
2008 Jul 21
2
CART and CHAID
Can I say that RPART is a modified algo of CART and PARTY a modified of
CHAID?
Thanks.
----
Chua Siang Li
Consultant - Operations Research
Acceval Pte Ltd
Tel: 6297 8740
Email: siang.li.chua at acceval-intl.com
Website: www.acceval-intl.com
This message and any attachments (the "message"...{{dropped:12}}