On 23-03-16 16:21, Moritz Lennert wrote:
Le Wed, 23 Mar 2016 15:55:40 +0100,
Paulo van Breugel <[email protected]> a écrit :
On 23-03-16 15:24, Anna Petrášová wrote:
On Wed, Mar 23, 2016 at 10:01 AM, Luca Delucchi
<[email protected]> wrote:
On 23 March 2016 at 14:31, Paulo van Breugel
<[email protected]> wrote:
Hi,
Hi,
I am using r.regression.multi in a python script (using
grass.run_command()) to compute the variance inflation factor
(VIF). It runs in a loop, regressing variables one by one to all
the other variables. It sometimes happen that the function fails
with:
WARNING: Matrix is unsolvable
ERROR: Multiple regression failed
This looks like a clear bug for me. So, even if I understand that you
need to work around it for now, could you also post a bug report with a
reproductible example ?
Not sure it is a bug? It happens when amongst the independent variables
there are perfectly correlated variables. The message "WARNING: Matrix
is unsolvable" therefore seems correct to me. Now this is treated as an
error (ERROR: Multiple regression failed"), which I guess is the
equivalent of grass.error() in a python script? Perhaps it would be
possible to provide a warning instead, and give an output that can be
captured, like NA for the coefficient estimates, instead of breaking of
the function?
Moritz
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