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Questions tagged [qr-decomposition]

1 vote
0 answers
55 views

Here is my attempt to show that INDSCAL as a special case of CANDELINC. I am using the following paper as my reference for definitions. Kolda, Tamara G., and Brett W. Bader. "Tensor ...
Omar Shehab's user avatar
12 votes
1 answer
464 views

I'm starting to more routinely mean-center and QR-rotate design matrices $X$ when doing maximum likelihood estimation (MLE) or Bayesian posterior sampling. This helps with convergence and quickens ...
Frank Harrell's user avatar
2 votes
1 answer
652 views

I am trying to understand the code from pybasicbayes, which defines the following function to sample from an inverse Wishart: ...
seeker_after_truth's user avatar
1 vote
1 answer
82 views

Assuming $\mathbf x_1$ and $\mathbf x_2$ are eigenvectors of matrix $\mathbf A \in \mathbb{R}^{2\times 2}$, there is $$\left(\mathbf I-\mathbf x_1\mathbf x_1^\top\right)\mathbf A\left(\mathbf I-\...
Aaron's user avatar
  • 11
1 vote
0 answers
101 views

I'm using rstanarm to estimate random slopes for second-order polynomial coefficients. My model has the basic form: ...
sjs_999's user avatar
  • 11
1 vote
0 answers
65 views

I am a recent enthusiast into linear modelling and working on a function in R that implements common calculations from lm in R, to better understand how it works. ...
tesla john's user avatar
1 vote
1 answer
917 views

I'm doing PCA in a covariance matrix where each column and row represents tenors of the yield curve. I have coded the Jacobi rotation method and I also have a QR algorithm based on numpy.linalg.qr in ...
sonarclick's user avatar
3 votes
0 answers
115 views

I apologize if this is the wrong place for this question; there are a number of potential points of failure each of which suggest either Math StackExchange or StackOverflow or here, but since the ...
cgmil's user avatar
  • 1,633
5 votes
2 answers
7k views

I am struggling to find a reference for this: In terms of big Oh notation does anyone know of any expressions for the computational time taken by commonly used algorithms for QR decompositions?
JDoe2's user avatar
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3 votes
1 answer
1k views

I know that the calculation of parameter values of a standard OLS can be made more efficient using a QR decomposition; i.e. if $X=QR$ and we are using the model $Y=X\beta+\epsilon$; Then it is true ...
JDoe2's user avatar
  • 690
2 votes
0 answers
207 views

Considering design matrix $X \in \mathbb{R}^{n\times p}$ $(n>p)$ and response $y\in \mathbb{R}^{n}$. The sandwich estimator can be calculated directly using $$(X^TX)^{-1}X^T diag(r^2) X (X^TX)^{-...
cccfran's user avatar
  • 75
3 votes
0 answers
765 views

I am using a linear regression, yet the only output I need is the Sum of Squared Residuals (SSR), I don't care about the coefficients. (Context is a non-linear LS, which is linear given an extra ...
Matifou's user avatar
  • 3,234
0 votes
0 answers
462 views

I am trying to understand if the ordering of columns matters in QR decompsoition. In general it seems that column ordering won't matter. I guess for SVD or any matrix factorization the way columns ...
mourinho's user avatar
  • 143
0 votes
2 answers
322 views

Suppose $Q_{1}$ is an $n$ x $p $ matrix (derived from the QR Decomposition of X) whose columns provide an orthonormal basis for the subspace ${\chi}$ of $\mathbb{R}^{n}$ spanned by the columns of an $...
roc11111111's user avatar
3 votes
1 answer
1k views

Here is the source code of R poly function (boundary checking are removed). Why we can use QR to build polynomial expansion, ...
HXD's user avatar
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