R help - May 2019 - Matrix::bdiag doesn't like being given a single named argument

Hello,

Perhaps not a bug, but interesting because the error only happens when 
there is a single named argument.

 ?? > m <- matrix(1, 1, 1)
 ?? > library(Matrix)
 ?? > bdiag(m)
 ?? 1 x 1 sparse Matrix of class "dgCMatrix"

 ?? [1,] 1
 ?? > bdiag(a = m)
 ?? Error in is.list(...) : supplied argument name 'a' does not match
'x'
 ?? > bdiag(a = m, b = m)
 ?? 2 x 2 sparse Matrix of class "dgCMatrix"

 ?? [1,] 1 .
 ?? [2,] . 1

Moreover, this works fine:

 ?? > bdiag(list(a = m))
 ?? 1 x 1 sparse Matrix of class "dgCMatrix"

 ?? [1,] 1

Thoughts?

Regards

Ben

My take would be that there is no reason to specify argument names at all when
calling bdiag, and clearly there is a reason to not do so.

The error seems to arise from using the S3 method is.list, which allows your
final example to work. is.list(a=1) clearly fails to match the x argument, but
is.list(list(a=1)) works just fine.

On May 31, 2019 6:25:19 AM PDT, Benjamin Tyner <btyner at gmail.com>
wrote:
>Hello,
>
>Perhaps not a bug, but interesting because the error only happens when 
>there is a single named argument.
>
> ?? > m <- matrix(1, 1, 1)
> ?? > library(Matrix)
> ?? > bdiag(m)
> ?? 1 x 1 sparse Matrix of class "dgCMatrix"
>
> ?? [1,] 1
> ?? > bdiag(a = m)
>?? Error in is.list(...) : supplied argument name 'a' does not match
>'x'
> ?? > bdiag(a = m, b = m)
> ?? 2 x 2 sparse Matrix of class "dgCMatrix"
>
> ?? [1,] 1 .
> ?? [2,] . 1
>
>Moreover, this works fine:
>
> ?? > bdiag(list(a = m))
> ?? 1 x 1 sparse Matrix of class "dgCMatrix"
>
> ?? [1,] 1
>
>Thoughts?
>
>Regards
>
>Ben
>
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