Dear R contributors,
Considering the following sample C code, that illustrates two possible
uses of a Cholesky decomp for inverting a matrix, equally valid at
least in theory:
SEXP test() {
int d = 2;
int info = 0;
double mat[4] = {2.5, 0.4, 0.4, 1.7};
double id[4] = {1.0, 0.0, 0.0, 1.0};
double
This isn't the help list for LAPACK, but as far as I can tell, dppsv expects a
symmetric matrix input compacted as triangular, not a Choleski decomposed one.
So try assigning lmat before the call to dpotrf.
-pd
> On 20 Dec 2014, at 22:06 , Pierrick Bruneau wrote:
>
> Dear R contributors,
>
Oh right, I just realized in the man that dppsv very likely decomposes
its A argument - instead of requiring a decomposed mat as I first
thought... So I was actually performing two successive Cholesky
decompositions ^^
On Sat, Dec 20, 2014 at 10:57 PM, peter dalgaard wrote:
> This isn't the help
This is an enquiry not so much about what the code for loadNamespace does,
but
rather about the intent and design of loadNamespace, and how it interacts
with
the `::` function, which seems to me to follow a slightly different
philosophy.
It is not an urgent question - the issue that started me w
