Displaying 20 results from an estimated 1000 matches similar to: "formula"
2004 Jul 13
2
help with as.function
HI, sorry but i don't understand how to make a function with as.function()
formula<-"2+3*x"
formu<-as.symbol(formula)
> formu
2+3*x
formul<-as.function(alist(x=,formu))
curve(formul,1,5,col="blue")
Error in xy.coords(x, y, xlabel, ylabel, log) :
x and y lengths differ
> typeof(formul)
[1] "closure"
and not plot the curve function, Why?
2001 Oct 23
2
Parsing of HTML files in R
Is there any package similar to the XML package that is able to
"extract" relevant information from HTML files. Namely, I'm interested
in obtained data that is represented as a HTML table, into some R-type
structure.
Thank you.
--
Luis Torgo
FEP/LIACC, University of Porto Phone : (+351) 22 607 88 30
Machine Learning Group Fax : (+351) 22 600 36 54
R. Campo
2004 Jul 15
2
formula and lm
Hi, don' t understand why the function fomula have this error, i enclose
the parameter "a" with the function I()
Thank Ruben
x<-1:5
y<-c( 2 ,4 , 6 , 8 ,11)
formu<-y~I(a*x)
form<-formula(formu)
dummy<-data.frame(x=x,y=y)
fm<-lm(form,data=dummy)
Error in unique(c("AsIs", oldClass(x))) : Object "a" not found
2005 Apr 27
2
its package: inexplicable date-shifting ?!
Can someone please explain to me why
the dates get shifted by one day
when I create an its ( irregular time-series )
object from a matrix for which I've
assigned row names.
E.g. in the example run below,
why does the its object have dates
one-shifted from my original dates?
> install.packages('its')
> install.packages('Hmisc')
> require(its)
> m <-
2005 Apr 27
1
Recursive calculation of a series of values
Dear R-users,
I'm felling kind of blocked on a quite simple problem and I wonder if
someone could give me a help with it.
My problem:
x[0] = 100
x[1] = (1+v[1])*x[0]
x[2] = (1+v[2])*x[1]
...
i.e.
x[i] = (1+v[i])*x[i-1]
and x[0]=k
Given a set of v values I wanted to obtain the corresponding x values in
an efficient way (i.e. without a for loop).
For instance, if x[0] = 100 and v =
2004 Oct 12
2
Statistical analysis of a large database
Deall all,
We need to perform a statistical analysis of a large database (40,000 entries with approximately 500 fields in each entry) currently handled in Oracle. The data contains categorical variables only.
At the current stage we suggest classification and clustering analysis.
We are planning to perform the analysis in R and would be very grateful for any
2003 Jun 05
1
kmeans (again)
Regarding a previous question concerning the kmeans function I've tried the
same example and I also get a strange result (at least according to what is
said in the help of the function kmeans). Apparently, the function is
disregarding the initial cluster centers one gives it. According to the help
of the function:
centers: Either the number of clusters or a set of initial cluster
2002 Apr 23
1
Writing text in lattice graphics
I'm trying to obtain a set of regression lines obtained for different values
of a factor using lattice. I would like to add a string to each panel showing
the R^2 value of the respective line, but I'm having difficulties positioning
the text (namely on which coordinates to give to the "ltext" function).
Here is what I'm using (I've used ?? for the things I would like
2002 Sep 12
1
DBI / MySQL problems
Hi.
I frequently use RMySQL package to interface R with MySQL databases. I was
having a try with package DBI and I got the following error:
> library(RMySQL)
> library(DBI)
> drv <- dbDriver("MySQL")
> ch <- dbConnect(drv, dbname="mydb", user="myuser", password="mypasswd")
> ibm <- dbGetQuery(ch,"select * from table where
2003 Nov 24
1
RMySQL valid field names
I'm having some problems with valid field names when using RMySQL to interface
R (version 1.7.0, under RedHat9.0), to MySQL (4.1.0-alpha). I think I've
spotted the problem and a solution (which is working for me), but I wanted to
share this with you as I may be missing something.
(Note: I'm aware that this is an old R version, but I've checked the code of
the lastest version of
2005 Oct 31
2
Sweave (R?) font encoding problems
Dear R list,
I'm having some problems with font encodings when using R+Sweave+Latex in my
native language: Portuguese.
My environment:
Kubuntu 5.10 Linux
$> uname -a
Linux nassa 2.6.12-9-686 #1 Mon Oct 10 13:25:32 BST 2005 i686 GNU/Linux
R> R.version
_
platform i486-pc-linux-gnu
arch i486
os linux-gnu
system i486, linux-gnu
2002 Nov 26
1
Problem with accented characters in portuguese
Dear all,
I've recently encountered a strange behaviour when using R with portuguese
accented characters. The most curious aspect is that using the same code with
ESS under XEmacs the behaviour is different.
My system is:
> R.version
_
platform i386-pc-mingw32
arch i386
os mingw32
system i386, mingw32
status
major
2005 Mar 29
1
regression tree xerror
I am running some models (for the first time) using rpart and am getting
results I don't know how to interpret. I'm using cross-validation to prune
the tree and the results look like:
Root node error: 172.71/292 = 0.59148
n= 292
CP nsplit rel error xerror xstd
1 0.124662 0 1.00000 1.00731 0.093701
2 0.064634 1 0.87534 1.08076 0.092337
3 0.057300 2
2006 Feb 02
2
R training courses
Hi All,
I am interested in learning about people's experience with R training or
courses. What worked, what didn't? What do you recommend?
Also, if there any groups or individuals that have and can offer R
training courses, please contact me directly. I would like to learn
about your services.
Thanks for your input and help. Please feel free to contact me directly.
Russ
2004 Sep 03
2
windowing strategies
Hello to everybody,
Does anyone has implemented a function for evaluating models using windowing
strategies, such as growing window or sliding window ones?
The aim is to evaluate regression models on a time series data. I do not use
cross-validation once data sorted in a radom way does not make sense when
evaluating time series.
Thanks
Joao Moreira
2009 Jan 24
3
Problem with colormodel in pdf driver
I'm trying to create figures in PDF that use the 'gray' colormodel
instead of the default 'RGB' model, by requirements of a publisher.
My problem has to do with the fact that I'm not being able to get gray
colors with this option on the pdf() driver. Here is a small example for
problem replication:
> R.version
_
platform
2004 Jul 06
1
R & DataMining
Dear R-user,
I wish to know if someone is using R as concern
Datamining or KDD (Knowledge Discovery in Database)
and if already exists a R package specialized in this
kind of analysis.
I found this contributes on the R web site:
[20] Diego Kuonen. Introduction au data mining avec R
: vers la reconqu??te du `knowledge discovery in
databases' par les statisticiens. Bulletin of the
Swiss
2007 Feb 23
2
Neural Net forecasting
Are there any packages in R that are suitable for doing time series
forecasting using neural networks? I have looked in the nnet package and
neural package and they both seem geared towards classification.
thanks,
Spencer
[[alternative HTML version deleted]]
2005 Jan 31
5
consultation
R people,
I need to know if is possible to make data mining with R. If so, is
there any manual or somewhere/one to consult about that.
Thank you very much
Adri?n
2011 Jan 29
1
environment question: changing variables from a formula through model.frame?
Hello all,
I came across a behavior of R with environments that I'm not sure what is
causing it.
It involves changing variables that are found through using model.frame on a
formula inside a function.
I wonder if it's a "bug" or a "feature". And in either case, how it might
be managed.
Here is a simple example:
# let's say we have an x and y variables:
temp_x