similar to: Matrix operations

Displaying 20 results from an estimated 5000 matches similar to: "Matrix operations"

2011 Mar 04
2
How to copy data from data.frame to matrix
Hello I'm a new in R I have a large data.frame "s" (this is actualy just a table in mysql) : > names(s) [1] "symbols", "day", "value" I need to convert it to simple matrix. I have define this matrix like this: > data.matrix <- matrix(nrow=nDays, ncol=nSymbols, dimnames=list(days, symbols)) then i just copy values to the matrix using for()
2011 May 18
1
How to make array of regression objects
Dear all, I have made couple logistic regressions, what making a distribution of some event. Currently, i store it like this: o1 <- lrm(...) o2 <- lrm(...) o3 <- lrm(...) ... Then, i have made a function to peak required regression object from this variables by it number: get_object <- function(obj_name, nModel) { eval (parse(text=paste("o <- ", obj_name, nModel,
2010 Sep 28
1
How to convert SEXP to double
Hello All, A simple question. I get some return from the R in my C++ program (via Rcpp package). The result come, as SEXP and it should be a simple numeric variable. How to convert it to double? The code, what i use: stringstream ss; ss << "p <- predict(fit_ar11, n.ahead = 2, doplot=FALSE);" << "p$pred[1]"; SEXP ans; int iRet =
2010 Apr 27
2
How to work out 3-way probabilities
Hello. I have a quick question. I try to use logit regression, to work out probabilities in the sport event. I have work out probabilities for group of 2 players: p1 - probability, what player1 will beat player2 p2 - probability, what player2 will beat player1 pt - tie probability, p1 <- 1 - p1 - p2; Now i want to work out probabilities for group of 3 players, like: pg1 - probability, what
2011 May 07
2
MDAC problems after last Wine path
Hello all. I'm using Fedora 14. I have patched my wine yesterday using yum, ane my wine current version is: 1.3.18-1.fc14. After that, some of my programs stop to working. It seems, what something happen with MDAC component, because program can't open mdb file and can not found MDAC component from the console. The errors. what i get: err:ole:CoGetClassObject class
2017 Feb 21
2
Linking Linux kernel with LLD
Maybe that is https://reviews.llvm.org/D30171. On Mon, Feb 20, 2017 at 11:16 PM, Dmitry Golovin <dima at golovin.in> wrote: > Hi, > > I can't build the Linux kernel anymore. With the latest kernel source and > latest LLVM and LLD (with D30163) I can only get this error message when > linking vmlinux: > > ld.lld: error: unable to move location counter backward >
2013 Mar 14
3
Error: did not find expected key while parsing a block mapping
I run test: test:units lass ProductTest < ActiveSupport::TestCase test "product attributes not be empty" do product = Product.new assert product.invalid? assert product.errors[:title].any? assert product.errors[:description].any? assert product.errors[:price].any? assert product.errors[:image_url].any? end test "price musst be
1999 Jul 20
2
tensor() function and sets
Hi Everyone, To complete the outer() and kronecker() functions in the base, may I suggest the following tensor() function, which allows the multiplication of arrays through sets of conformable dimensions. I am happy to write a help page if required. The code also needs a setdiff() function which prompts me to ask: what about simple set functions? I expect many of us have written our own
2004 Sep 20
4
Multiple operations on list
Hello, suppose I have a list with matrices: a=list(x1=matrix(rnorm(10),5,2),x2=matrix(rnorm(10),5,2),x3=matrix(rnorm(10),5,2)) I want to compute for all combination of xi and xj (x1,x2 x1,x3 and x2,x3) a value. This value is given for the pair x1,x2 by trace(x1%*%t(x1)%*%x2%*%t(x2)) / trace(x1%*%t(x1))*trace(x2%*%t(x2)) I know that product matrices t(xi)%*%xi can be obtained by:
2004 Jul 25
2
file index-mail-headers.c: line 408 (index_mail_get_header): assertion failed: (ret != 0)
FreeBSD 4.10-RELEASE, dovecot-1.0-test29 crashes on sort and thread commands: Jul 25 15:12:08 owl dovecot: imap-login: Login: dima [81.19.64.101] Jul 25 15:12:26 owl dovecot: IMAP(dima): file index-mail-headers.c: line 408 (index_mail_get_header): assertion failed: (ret != 0) Jul 25 15:12:26 owl dovecot: child 20384 (imap) killed with signal 6 (gdb) bt #0 0x281e0fc4 in kill () from
2010 Mar 27
1
R runs in a usual way, but simulations are not performed
Dear addresses, I need perform a batch of 10 000 simulations for each of 4 options considered. (The idea is to obtain the parameter estimates in a heteroskedastic linear regression model - with additive or mixed heteroskedasticity - via the Kenward-Roger small-sample adjusted covariance matrix of disturbances). For this purpose I wrote an R program which would capture all possible options (true
2006 Nov 21
1
crossprod(x) vs crossprod(x,x)
I found out the other day that crossprod() will take a single matrix argument; crossprod(x) notionally returns crossprod(x,x). The two forms do not return identical matrices: x <- matrix(rnorm(3000000),ncol=3) M1 <- crossprod(x) M2 <- crossprod(x,x) R> max(abs(M1-M2)) [1] 1.932494e-08 But what really surprised me is that crossprod(x) is slower than crossprod(x,x): R>
2016 Apr 19
2
state of the lld linker for aarch64
Hi, Some time ago there were some information about aarch64 support for the lld linker project: http://lld.llvm.org/open_projects.html#elf-aarch64 Right now there is no such information. Also there is some presentation described that the simple application can be linked using lld: http://llvm.org/devmtg/2016-03/Presentations/EuroLLVM%202016-%20New%20LLD%20linker%20for%20ELF.pdf What is the
2016 Apr 21
2
lld and linker scripts
Hi, I tried to use linker script with lld (this script works just file with GNU ld). I got a problem with defining new symbols and assign values (addresses) to them. For instance I got the following code in the linker script: SECTIONS { _exec_sym = 0; ... After using lld command with the --script option I got the following error: line 3: : expected, but got = _exec_sym = 0; ^ As
2002 Jul 01
1
samba PDC & XP
Hi I can't join to samba 2.2.5 PDC with WinXP. Is samba PDC works with XP? I use Samba-HOWTO-Collection.pdf, build smb.conf, but it doesn't work. debug level 0 doesn't show error, level 1 too. level 2 give 45k log, but I'm not good in samba. I could't understand, what happend. Could anybody help me? Dima mailto:samba@asv.ru
2005 Jan 27
3
the incredible lightness of crossprod
The following is at least as much out of intellectual curiosity as for practical reasons. On reviewing some code written by novices to R, I came across: crossprod(x, y)[1,1] I thought, "That isn't a very S way of saying that, I wonder what the penalty is for using 'crossprod'." To my surprise the penalty was substantially negative. Handily the client had S-PLUS as
2004 Oct 06
3
crossprod vs %*% timing
Hi the manpage says that crossprod(x,y) is formally equivalent to, but faster than, the call 't(x) %*% y'. I have a vector 'a' and a matrix 'A', and need to evaluate 't(a) %*% A %*% a' many many times, and performance is becoming crucial. With f1 <- function(a,X){ ignore <- t(a) %*% X %*% a } f2 <- function(a,X){ ignore <-
2002 Mar 15
1
Thought on crossprod
Hi everyone, I do a lot of work with large variance matrices, and I like to use "crossprod" for speed and to keep everything symmetric, i.e. I often compute "crossprod(Q %*% t(A))" for "A %*% Sigma %*% t(A)", where "Sigma" decomposes as "t(Q) %*% Q". I notice in the code that "crossprod", current definition > crossprod function (x,
2003 Oct 17
2
Problems with crossprod
Dear R-users, I found a strange problem working with products of two matrices, say: a <- A[i, ] ; crossprod(a) where i is a set of integers selecting rows. When i is empty the result is in a sense random. After some trials the right answer (a matrix of zeros) appears. --------------- Illustration -------------------- R : Copyright 2003, The R Development Core Team Version 1.8.0
2005 Oct 05
2
eliminate t() and %*% using crossprod() and solve(A,b)
Hi I have a square matrix Ainv of size N-by-N where N ~ 1000 I have a rectangular matrix H of size N by n where n ~ 4. I have a vector d of length N. I need X = solve(t(H) %*% Ainv %*% H) %*% t(H) %*% Ainv %*% d and H %*% X. It is possible to rewrite X in the recommended crossprod way: X <- solve(quad.form(Ainv, H), crossprod(crossprod(Ainv, H), d)) where quad.form() is a little