similar to: Unexpected behaviour of base::qr()$rank

2017-06-22 19:49 GMT+02:00 Uwe Ligges <ligges at statistik.tu-dortmund.de>: > On 22.06.2017 17:11, Bernd Funovits wrote: >> >> Hello, >> >> I experienced some unexpected behaviour while determining the rank of matrices (sometimes 1x1 matrices): >> base::qr(matrix(1e-20))$rank returns 1 (incorrect) >> base::qr(diag(c(1, 1e-20)))$rank returns 2

2017-06-22 20:31 GMT+02:00 Uwe Ligges <ligges at statistik.tu-dortmund.de>: > > > On 22.06.2017 20:09, I?aki ?car wrote: >> >> 2017-06-22 19:49 GMT+02:00 Uwe Ligges <ligges at statistik.tu-dortmund.de>: >>> >>> On 22.06.2017 17:11, Bernd Funovits wrote: >>>> >>>> >>>> Hello, >>>> >>>> I

On 22.06.2017 20:09, I?aki ?car wrote: > 2017-06-22 19:49 GMT+02:00 Uwe Ligges <ligges at statistik.tu-dortmund.de>: >> On 22.06.2017 17:11, Bernd Funovits wrote: >>> >>> Hello, >>> >>> I experienced some unexpected behaviour while determining the rank of matrices (sometimes 1x1 matrices): >>> base::qr(matrix(1e-20))$rank returns 1

Hi, I have noticed different rank values calculated by qr() depending on LAPACK parameter. When it is FALSE (default) a true rank is estimated and returned. Unfortunately, when LAPACK is set to TRUE, the min(nrow(A), ncol(A)) is returned which is only occasionally a true rank. Would not it be more consistent to replace the rank in the latter case by something based on the following pseudo code ?

I would like to find the rank of a matrix using R. Looking through a list of commands it seems that the command qr should do the job. Checking a simple example gave me the wrong answer. Here is the example: > A <- c(1,2,3,4,5,6) > A <- matrix(A, nrow=2, ncol=3) > A [,1] [,2] [,3] [1,] 1 3 5 [2,] 2 4 6 > qr(A)$rank [1] 3 The correct answer is two. I

I would like to find the rank of a matrix using R. Looking through a list of commands it seems that the command qr should do the job. Checking a simple example gave me the wrong answer. Here is the example: > A <- c(1,2,3,4,5,6) > A <- matrix(A, nrow=2, ncol=3) > A [,1] [,2] [,3] [1,] 1 3 5 [2,] 2 4 6 > qr(A)$rank [1] 3 The correct answer is two. I

Le 23/01/2018 ? 08:47, Martin Maechler a ?crit?: >>>>>> Serguei Sokol <sokol at insa-toulouse.fr> >>>>>> on Mon, 22 Jan 2018 17:57:47 +0100 writes: > > Le 22/01/2018 ? 17:40, Keith O'Hara a ?crit?: > >> This behavior is noted in the qr documentation, no? > >> > >> rank - the rank of x as

Le 22/01/2018 ? 17:40, Keith O'Hara a ?crit?: > This behavior is noted in the qr documentation, no? > > rank - the rank of x as computed by the decomposition(*): always full rank in the LAPACK case. For a me a "full rank matrix" is a matrix the rank of which is indeed min(nrow(A), ncol(A)) but here the meaning of "always is full rank" is somewhat confusing. Does it

I'm still trying to install R on my Irix machine. Now I have a new problem that crops up during the checks. I've found the root cause, and it's that R is returning zero for certain things for reasons I don't understand. 2.225073859e-308, entered directly into R, responds "2.225074e-308". 2.225073858e-308 responds "0". Their negative values respond

I'm still trying to install R on my Irix machine. Now I have a new problem that crops up during the checks. I've found the root cause, and it's that R is returning zero for certain things for reasons I don't understand. 2.225073859e-308, entered directly into R, responds "2.225074e-308". 2.225073858e-308 responds "0". Their negative values respond

In summary.manova the qr decomposition of a NxN matrix is calculated and for some cases is giving me a rank < N. However, following suggestions of professor Ripley to calculate the rank of a Matrix On 7 Jun 2002, Brian Ripley wrote: > For a more reliable answer, look at the SVD > (function svd) and look at the > singular values. For example (from lda.default) X.s <-

I use a 32 bit machine. For those using 64 bit machines, what is the .Machine$double.xmin for for machines? regards. Stephen. ----- Original Message ----- From: Achim Zeileis <Achim.Zeileis at wu-wien.ac.at> Date: Tuesday, July 12, 2005 10:51 am Subject: Re: [R] exact values for p-values - more information. > On Tue, 12 Jul 2005, S.O. Nyangoma wrote: > > > > If they

Dear R people, I do not have much knowledge about linear algebra but currently I need to understand what the function qr.qty is actually doing. The documentation states that it calculates t(Q) %*% y via a previously performed QR matrix decomposition. In order to do that, I tried following basic example: m<-matrix(c(1,0,0,0,1,0,0,0,1,0,0,1),ncol=3) # 4x3 matrix

With this example set.seed(123) A <- matrix(runif(40), nrow = 8) y <- 1:nrow(A) A.laqr <- qr(A, LAPACK=TRUE) both qr.qy(A.laqr,y) and qr.qty(A.laqr,y) give the respective error messages Error in qr.qy(A.laqr, y) : 'b' must be a numeric matrix Error in qr.qty(A.laqr, y) : 'b' must be a numeric matrix However when Lapack is not used as in A.liqr <- qr(A,

Dear maintainers, I'm reporting a bug in qr.coef that mishandles the colnames of matrix. A minimal reproducible example is as follows: x <- cbind(rep(0, 10), rep(0, 10)) y <- rep(0, 10) q <- qr.default(x) qr.coef(q, y) [1] NA NA If x has colnames, then qr.coef will end up with an error: x <- cbind(x1 = rep(0, 10), x2 = rep(0, 10)) y <- rep(0, 10) q <- qr.default(x)

R-1.7.0 built on NetBSD 1.6, but the validation test suite failed: Machinetype: Intel Pentium III (600 MHz); NetBSD 1.6 (GENERIC) Remote gcc version: gcc (GCC) 3.2.2 Remote g++ version: g++ (GCC) 3.2.2 Configure environment: CC=gcc CXX=g++ LDFLAGS=-Wl,-rpath,/usr/local/lib make[5]: Entering directory `/local/build/R-1.7.0/src/library' >>> Building/Updating

This behavior is noted in the qr documentation, no? rank - the rank of x as computed by the decomposition(*): always full rank in the LAPACK case. > On Jan 22, 2018, at 11:21 AM, Serguei Sokol <sokol at insa-toulouse.fr> wrote: > > Hi, > > I have noticed different rank values calculated by qr() depending on > LAPACK parameter. When it is FALSE (default) a true rank is

signif(.) is a <primitive> function. Unfortunately, I couldn't even find WHERE in the source, signif(.) is defined. Here are the symptoms: xmin <- .Machine $ double.xmin signif(xmin,3) #--> NA umach <- unlist(.Machine)[paste("double.x", c("min","max"), sep='')] for(dig in 1:10) {cat("dig=",dig,": ");

>>>>> Serguei Sokol <sokol at insa-toulouse.fr> >>>>> on Mon, 22 Jan 2018 17:57:47 +0100 writes: > Le 22/01/2018 ? 17:40, Keith O'Hara a ?crit?: >> This behavior is noted in the qr documentation, no? >> >> rank - the rank of x as computed by the decomposition(*): always full rank in the LAPACK case. > For a

Hi, Why the qr() produces a negative Q compared with Gram-Schmidt? (note example below, except Q[2,3]) Here is an example, I calculate the Q by Gram-Schmidt process and compare the output with qr.Q() a <- c(1,0,1) b <- c(1,0,0) c <- c(2,1,0) x <- matrix(c(a,b,c),3,3) ########################## # Gram-Schmidt ########################## A <- matrix(a,3,1) q1 <-