I have relied on the qr() function a lot in dealing with rank-deficient situations, but have recently run into some examples where it doesn't work correctly. Consider the matrix badX below: badX &l...

I'm currently trying to implement the Householder based QR decomposition for rectangular matrices as described in http://eprints.ma.man.ac.uk/1192/1/qrupdating_12nov08.pdf (pages 3, 4, 5). Apparen...

I have a question about converting a matlab function into R, and I was hoping that someone could help. The standard QR decomposition used in both matlab and R is referred to as qr(). To my underst...

I am currently building an application in R to calculate the QR matrix decomposition, the QR non negative matrix decomposition and computing ICA. At the moment I am working on the first task. I am ...

Avoiding array allocations is good for performance. However, I have yet to understand what is the most possible efficient way one can perform a QR decomposition of a matrix A. (note: both Q and R m...

I am trying to write a function for solving multiple regression using QR decomposition. Input: y vector and X matrix; output: b, e, R^2. So far I`ve got this and am terribly stuck; I think I have m...

I am working on a piece of code to find the QR factorization of a matrix in R. X <- structure(c(0.8147, 0.9058, 0.127, 0.9134, 0.6324, 0.0975, 0.2785, 0.5469, 0.9575, 0.9649, 0.1576, 0.9706, 0...

I'm trying to learn QR decomposition, but can't figure out how to get the variance of beta_hat without resorting to traditional matrix calculations. I'm practising with the iris data set, and here'...

I am trying to extend the lwr() function of the package McSptial, which fits weigthed regressions as non-parametric estimation. In the core of the lwr() function, it inverts a matrix using solve() ...

I'm trying to calculate in R a projection matrix P of an arbitrary N x J matrix S: P = S (S'S) ^ -1 S' I've been trying to perform this with the following function: P <- function(S){ output...

I have the the following Transform Matrix in CSS // rotate the element 60deg element.style.transform = "matrix(0.5,0.866025,-0.866025,0.5,0,0)" And i can find the rotation using this... // wher...

DGEQRF and SGEQRF from LAPACK return the Q part of the QR factorization in a packed format. Unpacking it seems to require O(k^3) steps (k low-rank products), and doesn't seem to be very straightfor...

I recently read about how the R matrix of QR decomposition can be calculated using the Choleski decomposition. The relation is: R = Choleski-decomposition(A^TA) Example: > A=matrix(c(1,2,3...

I am coding a QR decomposition algorithm in MATLAB, just to make sure I have the mechanics correct. Here is the code for the main function: function [Q,R] = QRgivens(A) n = length(A(:,1)); Q = ...

I'm trying to recover the R matrix from the QR decomposition used in biglm. For this I am using a portion of the code in vcov.biglm and put it into a function like so: qr.R.biglm <- function (o...