Displaying 20 results from an estimated 600 matches similar to: "Reading mixed tables"
2005 Nov 09
8
Element-by-element multiplication operator?
Is there an element-by-element multiplication in R, like the .* operator in Matlab?
eg: A (2x3)
B (2x3)
C=A.*B
C (2x3)
C = [[a11*b11 a12*b12 a13*b13]; [a21*b21 a22*b22 a23*b23]]
I can't find one...
Thanks
-Mike Gates
2007 Mar 10
3
long character string problem
Hi All
I am having 2 very long character strings (550chars) and I want to put them as
expressions together with c(). The problem is that I also get these
double-quotes, as seen below in 'fct'. How can I remove these double-quotes? I
tried as.name() but it did not work (because of size?). These are creating
trouble with subsequent programs, which I tested with strings that for some
2006 Dec 31
7
zero random effect sizes with binomial lmer
I am fitting models to the responses to a questionnaire that has
seven yes/no questions (Item). For each combination of Subject and
Item, the variable Response is coded as 0 or 1.
I want to include random effects for both Subject and Item. While I
understand that the datasets are fairly small, and there are a lot of
invariant subjects, I do not understand something that is happening
2006 Dec 31
0
(no subject)
> > If one compares the random effect estimates, in fact, one sees that
> > they are in the correct proportion, with the expected signs. They are
> > just approximately eight orders of magnitude too small. Is this a bug?
>
> BLUPs are essentially shrinkage estimates, where shrinkage is
> determined with magnitude of variance. Lower variance more
> shrinkage towards
2006 Dec 31
2
zero random effect sizes with binomial lmer [sorry, ignore previous]
I am fitting models to the responses to a questionnaire that has
seven yes/no questions (Item). For each combination of Subject and
Item, the variable Response is coded as 0 or 1.
I want to include random effects for both Subject and Item. While I
understand that the datasets are fairly small, and there are a lot of
invariant subjects, I do not understand something that is happening
here, and in
2009 May 19
4
nlrwr package. Error when fitting the optimal Box-Cox transformation with two variables
Dear all:
I'm trying to fit the optimal Box-Cox
transformation related to nls (see the code
below) for the demand of money data in Green (3th
Edition) but in the last step R gives the next
error message.
Error en
`[.data.frame`(eval(object$data), ,
as.character(formula(object)[[2]])[2]) :
undefined columns selected.
?Any idea to solve the problem?
Thanks in advance,
2008 Aug 12
2
Multiple column/row names?
Hi all,
I wonder if there is a way to create a matrix with two (or even more)
column/row names? Thank you very much.
Have a nice day.
--
??? Hesen Peng
http://hesen.peng.googlepages.com/
2008 Nov 23
2
How is R working in multicore and multiprocessor environment?
My Dear R buddies,
I'm feeling ashamed that I've been running my R program on some
servers for a while but do not know exactly how R is working. The
servers are chained together using Sun Grid Engine. Each node has 8
quad-core CPUs. I wonder how many cores and CPUs are used by a simple
single-thread R program. Thanks a lot.
Best wishes,
--
??? Hesen Peng
2010 Feb 04
1
Bug in as.character? (PR#14206)
A long formula which is converted using as.character, looses its last
part: ``diagonal = 1e-12)''
Shorter formula is ok though.
Best,
H??vard
************
Browse[2]> formula.str
y ~ -1 + b1 + b2 + b3 + b4 + b5 + b6 + b7 + b8 + b9 + b10 + b11 +
b12 + b13 + b14 + b15 + b16 + b17 + b18 + b19 + b20 + b21 +
b22 + b23 + b24 + b25 + b26 + b27 + b28 + b29 + b30 + b31 +
b32 +
2008 Jun 23
3
Simulating Gaussian Mixture Models
Hi,
Is there any package that I can use to simulate the Gaussian
Mixture Model , which is a mixture modeling method that is widely used
in statistical learning theory.
I know there is a mclust, however, I think it is a little bit
different from my problem.
Thanks very much..
regards.
--------------------------
Peng Jiang
??
Ph.D. Candidate
Antai College of Economics &
2010 Jan 07
1
faster GLS code
Dear helpers,
I wrote a code which estimates a multi-equation model with generalized
least squares (GLS). I can use GLS because I know the covariance matrix of
the residuals a priori. However, it is a bit slow and I wonder if anybody
would be able to point out a way to make it faster (it is part of a bigger
code and needs to run several times).
Any suggestion would be greatly appreciated.
Carlo
2008 Sep 11
1
Convex optimization in R?
Hi my R buddies,
I'm trying to solve a specific group of convex optimization in R. The
admissible region is the inside and surface of a multi-dimensional
eclipse area and the goal function is the sum of absolution values of
the variables. Could any one please tell me whether there's a package
in R to do this? Thank you very much,
Best wishes,
--
??? Hesen Peng
2009 Jul 11
1
Conditional expand.grid()
Hello my R buddies,
I'm trying to generate a bivariate data.frame with the elements of
first row greater than the second row. The more complicated method
that I can think of is:
n <- 10
temp <- expand.grid(1:n,1:n)
temp<-temp[temp[,1]>temp[,2],]
However, I guess there must be some easier way of doing this. Besides,
if inequality condition is applied at the very
2008 Oct 03
1
When to set small values to 0?
My dear R buddies,
I've run into a problem when doing numerical computation recently. In
a program that I've been working on, I usually get a vector of real
values which are theoretically (and it's correct) supposed to decrease
until reaching zero after a given value. However, most of the value
just wander at 10^-8 scale and never shrink exactly to zero. So I
guess I should manually
2008 Nov 24
2
More than doubling performance with snow
Hey my R buddies,
I installed the "snow" and "rpvm" package on my Lenovo Thinkpad T400
today. The experiment below gave me a surprise. The time consumed by
serial processing was several times larger than that taken by parallel
processing. I'm very curious how this happened. Thank you very much.
> library(snow)
>
> cc <- makePVMcluster(2)
>
> temp <-
2008 May 18
2
*apply function for arrays?
Hi all,
I've recently been writing functions which may deal with very large
arrays. And I hope to use *apply functions in the program so that the
code may look nicer and the performance may be better in the following
two situations.
The first situation is:
I'm having an array A with dim(A)==c(m,n,p). And I want to apply a
function F to a group of elements in A like:
1) F is applied to
2010 Apr 13
1
Lapack, determinant, multivariate normal density, solution to linear system, C language
r-devel list,
I have recently written an R package that solves a linear least squares
problem, and computes the multivariate normal density function. The bulk
of the code is written in C, with interfacing code to the BLAS and
Lapack libraries. The motivation here is speed. I ran into a problem
computing the determinant of a symmetric matrix in packed storage.
Apparently, there are no explicit
2009 Oct 27
1
How to express a tree?
Hello everybody,
I'm write a function whose output represents a tree. Can anyone please
recommend me some data structure in R which are good for expressing a
tree? The possible idea I'm having in my mind is to represent the
whole tree as a list in which a sublist (an element to the main list)
contains all its corresponding branches. Is there any simpler way of
doing this? Thank you very
2013 Apr 22
7
Multiple lon lat points in the map with ggplot2
Hello R users,
For the last few days I am struggling with the following task:
my data.frame:
A1 A2 A3 B1 B2
B3
58.81 53.292 54.501 13.013 17.39 19.407 56.02 56.251 54.033 20.099 13.15
10.411 55.376 53.099 57.625 13.396 21.031 13.22 58.584 53.194 54.218
13.038 16.854 19.289 55.7 55.921 53.847 19.942 13.153 9.828 55.093 52.934
2012 Nov 14
1
R wildcards, sapply and as.factor
I want to change the type to factor of all variables in a data frame whose names match a certain pattern.
So here I am trying to change the type to factor of all variables whose name begins with?namestub?in the dataframe?df.
attach(df)sapply(grep(glob2rx("namestub*"),names(df)),as.factor)
But this doesn't work since
>levels(df$namestub1)NULL