[R] problems with rq.fit.sfn

[alessia matano]

Dear all,

I am running a quantile estimation with Sparse matrix and when I run
the procedure rq.fit.sfn I receive the following warning: tiny
diagonals replaced with Inf when calling blkfct.
Does anyone knows exactly what does it mean? What's this kind of
error? Should I get worried about this message?
 The matrix I use is a full rank matrix (and indeed I do not have any
message about singularity problems).
Many thanks for your help
alessia