Displaying 20 results from an estimated 2000 matches similar to: "stats lm() function"
2007 Aug 16
4
Linear models over large datasets
I'd like to fit linear models on very large datasets. My data frames
are about 2000000 rows x 200 columns of doubles and I am using an 64
bit build of R. I've googled about this extensively and went over the
"R Data Import/Export" guide. My primary issue is although my data
represented in ascii form is 4Gb in size (therefore much smaller
considered in binary), R consumes about
2009 Mar 31
1
error during DPpackage compilation
Dear All,
I've had trouble compiling DPpackage as a user in one system. It works fine
as root in other machines.
I can see any clues in error messages My guess is that it is a permissions
matter.
Any help is appreciated.
OS: Linux
Kernel: 2.6.27 SMP
Arch: Intel 64 bits
gfortran not available
Thank you.
----------------------><8-------------------------------------
g77 ? -fpic ?-g
2006 Apr 24
1
Handling large dataset & dataframe [Broadcast]
Here's a skeletal example. Embellish as needed:
p <- 5
n <- 300
set.seed(1)
dat <- cbind(rnorm(n), matrix(runif(n * p), n, p))
write.table(dat, file="c:/temp/big.txt", row=FALSE, col=FALSE)
xtx <- matrix(0, p + 1, p + 1)
xty <- numeric(p + 1)
f <- file("c:/temp/big.txt", open="r")
for (i in 1:3) {
x <- matrix(scan(f, nlines=100), 100,
2009 Mar 25
3
very fast OLS regression?
Dear R experts:
I just tried some simple test that told me that hand computing the OLS
coefficients is about 3-10 times as fast as using the built-in lm()
function. (code included below.) Most of the time, I do not care,
because I like the convenience, and I presume some of the time goes
into saving a lot of stuff that I may or may not need. But when I do
want to learn the properties of an
2006 Aug 21
1
Retrieving p-values and z values from lmer output
I can't find a way to retrieve z values and p-values from the output
from lmer in the lme4 package. How is this done?
Rick B.
2006 Jul 04
1
lmer print outs without T
Hi,
I have been having a tedious issue with lmer models with lots of
factors and lots of levels. In order to get the basic information at
the beginning of the print out I also have to generate these enormous
tables as well. Is there a method command to leave off all of the
effects and correlations? Or, do I have to go to string commands?
2006 Jul 15
3
names() function and lmer()
Hello All,
I would like to retrieve some of the results from the lmer(...)
function in library lme4. If I run a model, say
fm.1 <- lmer(y ~ 1 + (1 | x), data = dog)
and try names(fm.1), I get NULL. Is there anyway to retrieve the information?
Thanks
2008 Jun 12
2
[LLVMdev] code generation order revisited.
On Tue, 06 May 2008 16:06:35 -0400, Gordon Henriksen wrote:
> On 2008-05-06, at 13:42, Hendrik Boom wrote:
>
>> One more question. I hope you're not getting tired of me already. Does
>> generating LLVM code have to proceed in any particular order?
>>
>> Of course, if I am writing LLVM assembler by appending characters to
>> the
>> end of a sequential
2008 Jun 12
0
[LLVMdev] code generation order revisited.
On Jun 12, 2008, at 11:38, Hendrik Boom wrote:
> On Tue, 06 May 2008 16:06:35 -0400, Gordon Henriksen wrote:
>
>> On 2008-05-06, at 13:42, Hendrik Boom wrote:
>>
>>> One more question. I hope you're not getting tired of me already.
>>> Does generating LLVM code have to proceed in any particular order?
>>>
>>> Of course, if I am writing
2007 Oct 03
1
inverse of matrix made by low.tri function
Hi all,
I am using R trying to get a inverse matrix of (X^T)X , but I keep getting
the error
message like: no b argument and no default value for sprintf(gettext(fmt,
domain = domain), ...) .
--------------------------------------------------------------------------------------------
# my code
X<-Matrix(rep(1,500),100,5)
X[lower.tri(X)]<-1-10^-7
XtX<- t(X)%*% X
XtXu<-lu(XtX)
2012 Aug 07
1
lm with a single X and step with several Xi-s, beta coef. quite different:
Hi, (R version 2.15.0)
I am running a pgm with 1 response (earlier standardized Y) and 44
independent vars (Xi) from the same data =a2:
When I run the 'lm' function on single Xi at a time, the beta
coefficient for let's say X1 is = -0.08 (se=0.03256)
But when I run the same Y with 44 Xi-s with the 'step' function (because
I left direction parameter empty, I assume a backward
2011 Oct 05
6
reporting multiple objects out of a function
Dear folks,
I?m trying to build a function to create and make available some variables I
frequently use for testing purposes. Suppose I have a function that takes
some inputs and creates (internally) several named objects. Say,
fun1 <- function(x, y, z) {obj1 <- x; obj2 <- y; obj3 <- z
<missing stuff>
}
Here is the challenge: After I run it, I want the objects to be
2006 Jan 19
4
multiple database in the same actions?
Hi,
I read the example in
http://wiki.rubyonrails.com/rails/pages/HowtoUseMultipleDatabases,
it show us how to connect to other database, each time
we start a new action, however, this doesn''t work
while you try to connect to two different database
within the same action.
SO I wonder is it possible to bind to two or more
database within the same action????
Thanks you very much
Saiho
2011 Aug 16
2
generalized inverse using matinv (Design)
i am trying to use matinv from the Design package
to compute the generalized inverse of the normal equations
of a 3x3 design via the sweep operator.
That is, for the linear model
y = ? + x1 + x2 + x1*x2
where x1, x2 are 3-level factors and dummy coding is being used
the matrix to be inverted is
X'X =
9 3 3 3 3 3 3 1 1 1 1 1 1 1 1 1
3 3 0 0 1 1 1 1 0 0 1 0 0 1 0 0
3 0 3 0 1 1 1 0 1 0 0 1
2011 Aug 28
2
converting matrix in array
Hi everyone,
have a small problem trying to converting a dataset in matrix form to an
array.
Specifically: data include 3D measurement -x,y,z of 59 points in 36 objects.
They are stored as a matrix (x) of 2124 rows and 3 columns.
What I want to do is to extract each subject's dataset using an array (b).
Accordingly, I tried the following command:
b<-array(a,c(59,3,36)).
The problem is
2005 Jan 11
5
global objects not overwritten within function
Dear useRs,
I have a function that creates several global objects with
assign("obj",obj,.GlobalEnv), and which I need to run iteratively in
another function. The code is similar to
f <- function(...) {
assign("obj",obj,.GlobalEnv)
}
fct <- function(...) {
for (i in 1:1000)
{
...
f(...)
...obj...
rm(obj) #code fails without this line
}
}
I don't understand
2012 Jul 24
1
Function for ddply
Hello, all. I'm new to R and just beginning to learn to write functions. I
know I'm out of my depth posting here, and I'm sure my issue is mundane.
But here goes. I'm analyzing the American National Election Study (nes),
looking at mean values of a numeric dep_var (environ.therm) across values
of a factor (partyid3). I use ddply from plyr and wtd.mean from Hmisc. The
nes requires a
2004 Jan 16
2
reference to objects
Hi,
is there a way to reference to a data object without copying it?
For example I have a huge matrix called dist and I want two objects
obj1 and obj2 to have a memeber dist that points to the matrix, but
I don't want, for memory reasons, to copy the matrix twice.
As far as I understand the following code will generate three copies
of my data:
dist <- some_code_that_generates_data
2006 Jul 07
3
attach and detach question
I have a large R program that I am constantly running over and over again. At the beginning of this program, I create a hige matrix and a huge dataframe but these are constant. What I mean by constant is that, if I run the program over later, I really should just use the old matrix and dataframe ( if they exist ) that were created in a previous run so that the program doesn't have to spend
2010 Dec 26
4
how to replace my double for loop which is little efficient!
Dear all,
My double for loop as follows, but it is little efficient, I hope all
friends can give me a "vectorized" program to replace my code. thanks
x: is a matrix 202*263, that is 202 samples, and 263 independent variables
num.compd<-nrow(x); # number of compounds
diss.all<-0
for( i in 1:num.compd)
for (j in 1:num.compd)
if (i!=j) {
S1<-sum(x[i,]*x[j,])