>>>>> Kun Ren
>>>>> on Sat, 19 May 2018 08:17:37 +0000 writes:
> 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)
> qr.coef(q, y)
> Error in qr.coef(q, y) : object 'pivotted' not found
> This happens only when x any y are all zeros. I found this problem when I
implement a qr-based wls which stops when all weights are zero and the x matrix
has colnames.
> A brief debug on qr.coef shows that when `nam` is not NULL, no branch of
code leads to creating `pivotted` before using it finally.
Dear Kun,
this is indeed a bug, and I will address it.
Thank you very much for the reprex (:= [repr]oducible [ex]ample)!
Best,
Martin Maechler
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