Displaying 20 results from an estimated 5000 matches similar to: ""Chow Test" for classification and regression trees"
2009 May 17
2
Chow test(1960)/Structural change test
Hi,
A question on something which normally should be easy !
I perform a linear regression using lm function:
> reg1 <- lm (a b+c+d, data = database1)
Then I try to perform the Chow (1960) test (structural change test) on my regression. I know the breakpoint date. I try the following code like it is described in the “Examples” section of the “strucchange” package :
> sctest(reg1,
2009 May 27
1
C4.5 implementation in R
Greetings,
Does anyone know if the C4.5 algorithm is already implemented in R? If yes,
please let me know the package. Thanks.
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2009 Dec 16
2
rcart - classification and regression trees (CART)
Hi,
I am trying to use CART to find an ideal cut-off value for a simple
diagnostic test (ie when the test score is above x, diagnose the condition).
When I put in the model
fit=rpart(outcome ~ predictor1(TB144), method="class", data=data8)
sometimes it gives me a tree with multiple nodes for the same predictor (see
below for example of tree with 1 or multiple nodes). Is there a way
2007 Jun 06
1
Chow Test
Hello R-users!
I tried to find a package to run a CHOW TEST. As a reference package I found
the STRUCCHANGE package. Do you know if it works well otherwise can you
recommend a different one?
Thanks, Bernd
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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] :
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
2007 Feb 23
1
Repeated measures in Classification and Regresssion Trees
Dear R members,
I have been trying to find out whether one can use multivariate
regression trees (for example mvpart) to analyze repeated measures data.
As a non-parametric technique, CART is insensitive to most of the
assumptions of parametric regression, but repeated measures data raises
the issue of the independence of several data points measured on the
same subject, or from the same plot
2011 Jan 09
1
question about the chow test of poolability
Good day R-listers,
My question is more a statistical question than an R related question,
so please bear with me
i'm currently applying the chow test of poolability
in fact i'm working with panel N=17 T=5 , and my model looks like
this : Yit= a0+B1X1+B2X2+B3X3+B4X4+eit
My question is the following when i'm Testing for the equality of
the coefficients of the unpooled data (the
2005 Oct 18
2
Classification tree data structure
Hi there,
I am growing classification trees using the 'tree' package add-on to R.
I would like to convert the 'R' output to the SAS format used by Salford Systems' commercial CART software in order to interface with some
other software.
My question is:
How can I parse the R tree data structure in order to infer the tree structure? The 'tree' class has a member
2008 Jun 17
1
Decision Trees RWeka
Hello,
I have a question concerning decision
trees coming from RWeka :
library(RWeka)
m =J48(Species~.,data=iris)
How could such a decision tree be transferred
into a matrix, pretty much in the same fashion,
as it is done by getTree() in library(ofw)
library(ofw)
data(srbct)
attach(srbct)
##ofwCART
learn.cart.keep <- ofw(srbct,
2009 Nov 01
5
Headache with sessions being shared.
I have a really horrendous problem with sessions.
before_filter :find_cart_from_session
private
def find_cart_from_session
if session[:cart] # if there''s is a cart in the session
begin
@cart = Cart.find(session[:cart]) # return existing or new cart
rescue ActiveRecord::RecordNotFound
@cart = Cart.create
@cart.save
session[:cart] = @cart.id
2007 May 30
2
Depot - empty_cart with ajax
First of all id like to say hi to everyone from Argentina, im yet
another Depot first-timer.
Going through the example, i got to the point where my cart finally
runs Ajax-based. And there is a line where Dave says, after all the
job is done "You should see the cart in the sidebar update. And you
shouldn''t see your browser show any indication of reloading the page.
You''ve
2006 Aug 16
2
Q on AJAX with respect to DRY
I have a shopping cart function, and I''d like to set it up to update the
cart with AJAX. My AJAX call will return a view that displays the cart
items.
My question is with regards to keeping things DRY. When the user goes to
"view cart", that page needs to display the cart, then the cart display
needs to update with AJAX calls when items are added from that page. It
would
2017 Jun 13
2
Classification and Regression Tree for Survival Analysis
I am trying to use the CART in a survival analysis. I have three variables of interest (all 3 ordinal - x, y and z, each of them with 5 categories) from which I want to make smaller groups (just an example 1st category from X variable with the 2nd and 3rd categories from the Y category and 2, 3 and 4 categories from the Z category etc) based on their, let's say, association with mortality.
Now
2007 Feb 07
1
The Depot "Add to Cart" sessions question (2.ed agile book)
Hello,
Im in the process of working my way through the 2.ed of the agile book.
As many of you already know, the book goes through the regular
development cycle of the Depot application. I have hit a wall
when they started talking about the sessions and the exact mechanics of
how an item is added to the session.
The code looks like this:
depot/app/controllers/store_controller:
def add_to_cart
2006 Aug 04
6
Errors ... errors and errors.
I bought the second edition of the ruby on rails, it seems to work fine
now, did some adjustments to the code. But now I get a second error and
I want to learn to understand to fix them myself. So here is the error.
ArgumentError in StoreController#add_to_cart
wrong number of arguments (1 for 0)
#{RAILS_ROOT}/app/models/cart.rb:15:in `initialize''
#{RAILS_ROOT}/app/models/cart.rb:15:in
2006 Apr 16
9
''depot'' app, where''s session?
Many of you probably know the ''depot'' app from the ''Agile Rails
development'' book.
I have constructed the ''products'' model, the Store-controller, and the
''Cart'' and ''Line Item'' classes. I have told Application-controller about
:cart and :line_item:
model :cart
model :line_item
Here''s part of
2005 Nov 25
4
BlindDown recommendations?
Hi folks,
I''m putting together a site that will have a shopping cart tab along the
top which, when clicked, slides down to reveal the full contents of
the cart (covering the page underneath it).
When designing it and getting the styling right, I had the page display
the cart fully open by default. This worked fine - the cart can close
and open any number of times without problem[1].
2007 Feb 16
6
some fun functionality for all your specs
I''ve found these two snippets of code useful and would love some feedback.
first, .should_have_valid_associations
usage:
context "A new Product" do
specify "should have valid associations" do
@product.should_have_valid_associations
end
end
code: (thanks to Wilson/Defiler for converting to rspec)
module Spec
module Expectations
module Should
2006 Jun 23
3
Yet another problem with NoMethodError in Store#display_cart
Hi everybody,
I''ve search a lot on google to help me with this one without success. I
know that some people had the same problem as I have, but there
solutions doesn''t seems to work for me.
I''m trying to do the depot example in the AWDwR book. But now I''m stock
with a problem that I can''t solve. I get this error:
<--- begin error here --->