similar to: predict.lm with missing data

Displaying 20 results from an estimated 10000 matches similar to: "predict.lm with missing data"

2001 Nov 26
3
Doing things with POSIXt
Dear R-Users, I have a data file with timestamps and I wanted to use POSIXct time data type to represent the respective column. I played around with the type and found a couple of issues: * there seems to be no direct way of reading datetimes into a variable. Let's say this is my file "1992-02-27 23:03:20 PST" "1992-02-27 22:29:56 PST" "1992-01-14 01:03:30 PST"
2001 Jul 20
3
estimation of drift of continuous random walk
Dear R-Users, I have the following problem to solve and I wonder if there are means in R that can help me. At irregular time intervals I observe a random walk process, Y, with time-varying drift. I assume that the drift, D, is a (linear) function of some parameter X. The goal is to estimate D(X). I could regress Y_{t+dt} - Y_{t} ~ X, but it's probably not appropriate since Var(Y_{t+dt} -
2001 Oct 27
2
"unloading" data
Dear R-Users, I am reading the "An Introduction to R" manual and have come across data() function for loading data. I assume that R requires explicit loading of data objects to save memory. Then I'd expect there should be a function that can unload the objects once they are not needed anymore, what is this function? It would be helpful if ?data contained a reference to that
2001 Sep 17
3
computational capacity of Linux network
Hi, This is not an R question per ce, but I feel like this is a right community to ask it. As a part of our work we run a lot of non-interactive computational jobs. To increase the throughput we would like to distribute the load over the entire network and we are looking at Linux network as a platform. Ideally we would like to be able to submit a job to the network, rather than to a computer, and
2001 Nov 23
4
SQL implementations (was: Are you experienced in SAS and R ...)
An embedded message was scrubbed... From: Douglas Bates <bates at stat.wisc.edu> Subject: Re: [R] Are you experienced in SAS and R as well? Which of these would you recommend me? Date: 23 Nov 2001 15:16:59 -0600 Size: 4446 Url: https://stat.ethz.ch/pipermail/r-help/attachments/20011123/8d0399f0/attachment.mht
2002 Jul 13
3
mutable objects
Hi, I need "mutable" objects that I can safely modify in my C code. All call interfaces, e.g. .C, .Call, etc., require you to not modify the "in" args. The description of the OOP package in R-news from Sep 2001 alludes to a possiblity of such objects, but the package itself is no longer on Omegahat and I am not sure I need the full machinery. Thanks, Vadim P.S. I wonder
2002 Nov 11
2
listing objects loaded by load()
Hi, Is there a direct way of listing objects loaded by load() command? I worked around by loading into a new environment and then ls() of that environment, but I wonder if there is a simpler way. Thanks, Vadim -------------------------------------------------- DISCLAIMER This e-mail, and any attachments thereto, is intended only for use by the addressee(s) named herein and may contain legally
2002 Jun 28
1
browser/debug and for loop
Dear R-Users, It seems like once one invokes browser() inside a loop and steps through the body using 'n' any subsequent loop will be "intercepted" by debug() function. Here is exactly what I mean # fresh R session # run a loop that has browser() inside the body > for (i in seq(5)) { browser(); print(i) } for (i in seq(5)) { browser(); print(i) } Called from: NULL
2002 Apr 29
2
calling optim from external C/C++ program
Hi, Does anyone have an example of calling optim() from a standalone C/C++ program? If possible please include the linker options (I am using gcc version 2.96 20000731 (Red Hat Linux 7.1 2.96-98)) Thanks, Vadim -------------------------------------------------- DISCLAIMER This e-mail, and any attachments thereto, is intended only for use by the addressee(s) named herein and may contain
2003 Apr 02
8
lm with an arbitrary number of terms
Hello folks, Any ideas how to do this? data.frame is a data frame with column names "x1",...,"xn" y is a response variable of length dim(data.frame)[1] I want to write a function function(y, data.frame){ lm(y~x1+...+xn) } This would be easy if n was always the same. If n is arbitrary how could I feed the x1+...+xn terms into lm(response~terms)? Thanks Richard -- Dr.
2002 Dec 02
1
readLines() changes mode of connection
Hi, It seems like reading a line from a gzfile() connection changes the mode of the connection from text to binary (it also alters "can write", in case it matters). The following transcript, produced on RedHat 7.1, demonstrates this "feature" (note the evolution of file$text). Is this expected? Thanks, Vadim > file <- gzfile("foo.gz") file <-
2003 Mar 11
2
system(..., intern=TRUE) splits long lines (PR#2623)
system(..., intern=TRUE) splits long lines after 118th character and discards the 119th character > a <- paste(rep("a", 124), collapse="") > system(paste("echo", a), intern=TRUE) system(paste("echo", a), intern=TRUE) [1] "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2003 Apr 23
9
sum
Dear helpers I have a list where each element is a matrix (the list is obtained with lapply). I want to sum those matrices. Is there a function to do that? The sum function sums all the elements... -- http://adsl.sapo.pt
2002 Aug 09
1
LM: Least Squares on Large Datasets OR why lm() is designed the w ay it is
Hi, I have always been wondering why S-Plus/R can not fit a linear model to an arbitrary large data set given that, I thought, it should be pretty straightforward. Sometime ago I came across a reference to LM package, http://www.econ.uiuc.edu/~anovo/LM.html, by Roger Koenker and Alvaro Novo. So I thought here it is at last, but to my surprise this project hasn't made to the recommended
2003 Feb 19
4
fitting a curve according to a custom loss function
Dear R-Users, I need to find a smooth function f() and coefficients a_i that give the best fit to y ~ a_0 + a_1*f(x_1) + a_2*f(x_2) Note that it is the same non-linear transformation f() that is applied to both x_1 and x_2. So my first question is how can I do it in R? A more general question is this: suppose I have a utility function U(a_i, f()), where f() is say a spline. Is there a general
2002 Dec 19
1
disabling NA token as na.string in read.table
Dear R-Users, I have a csv file that has NA tokens and these tokens are perfectly good values that need not to be converted to NA by read.table(). I tried to prevent the conversion by specifying the na.strings arg., but this seems to only add to the list of NA strings, not substitute. > system("cat foo") system("cat foo") 1 foo 2 NA > read.table("foo",
2001 Nov 06
1
RPM digital signature
I thought I'd install the binary RPM for Red Hat 7.1. Following the advice from the ReadMe I checked the GPG signature (sorry, I have very little idea what it is) of the .rpm files. Here is what I got. % rpm --checksig *.rpm R-base-1.3.1-3.i386.rpm: md5 GPG NOT OK R-recommended-1.3.1-1.i386.rpm: md5 (GPG) OK (MISSING KEYS: GPG#97D3544E) Does it indicate any problem? Thanks, Vadim
2002 Jan 03
1
skipping fields in scan()
Dear R-Users, Is it possible to instruct scan() to skip fields when reading from a file. Here is an example. Suppose I have a three-column table file, "foo" 1 2 3 4 5 6 and I want to read in only the first and the third columns skipping the second. If memory serves me well (though I might be wrong), in S-Plus you could accomplish this by putting NULL in the respective position of the
2002 Nov 27
1
read.table: colClasses when num. of columns is unknown
Hi, I am looking for a way to read tables that have general structure of characterTag num1 num2 ... i.e. one character column followed by an unknown to the caller (but fixed throughout the file) number of numeric columns. I wanted to improve the speed of read.table by using colClasses, but that seemed to require knowledge of the actual number of columns in the file. For example I tried
2002 Dec 30
2
Writing packages with `methods' package
I'm trying to write a package which uses classes/methods as defined in the `methods' package. I have a single .R file which defines the class and various methods for that class. At the top of the file I have require(methods) and then setClass("myclass", ...) setGeneric("intersect") setMethod("intersect", "myclass", function(x,y) ...) I noticed