Hi Pantelis, All,

2009/12/30 chung <chvng at mail.ntua.gr>:

> When my RDF parser detects an empty string or a value that should be
> numeric but cannot be cast as such, it overrides it and considers of it
> to be missing. I'll try to fix that - I just need one more check in a
> critical step of the RDF parsing, so I think it wont be very difficult.
> The message "Can't Handle class attribute" (because the class attribute
> is of type String) appears because there is some non-numeric entry for
> the specified target feature which characterizes the whole feature as
> String.

I just want to clarify that this error occurs (very) rarely and is
difficult to reproduce. It might be exhibited only under periods of
high load of the services (e.g. when they receive 10 consecutive
requests for model training), though I'm not sure whether high load is
the real trigger. However, it is important to keep in mind that the
error occurs with the same dataset/feature URIs, for which in the
majority of cases model training succeeds. So, perhaps, in this
particular case, it is not due to any persistent (source) data issues,
but has rather something to do with the way data is transmitted and/or
processed at lower levels. The POST under load issue that Nina has
solved with code migration to Noelios-Restlet/2.0m6 might be the
culprit (I've noticed you're still using Noelios-Restlet/2.0m3),
however this is just a (very) wild guess...

> Many issues will be fixed if we establish datatype declarations
> for features.

Agreed -- in any case this is something we should discuss and decide
upon during the next virtual meeting.

Best regards,
Vedrin