[Qgis-developer] Wrong $length

[Nyall Dawson]

On 25 Dec 2014 12:37 am, "Paolo Cavallini" <cavallini at faunalia.it> wrote:
>
> Hi all.
> The calculation of $length on the attached file returns weird results:
> when calculated as virtual field is ok, whereas when updating an
> existing field a negative result is given. I assume this is related to
> topological errors in the line, but nevertheless the diff between the
> two methods is unexpected.
> Furthermore, "Update all" does not seem to work on a column where
> sorting is applied (by clicking on column head).

I can't test right now, but this sounds like possibly the column isn't
large enough to hold the length values, and they are overflowing into
negative values. Could this be the case?

Nyall
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