Function psVectorStats argument errors

[Eric.VanAlst@…]

In SDR-08 section 4.3.1, the function psVectorStats has a new argument named
errors, but there is no description of its intended use. Does it need to be of
a specific type?

[Paul Price]

Added that "the \code{errors} must be of the same type as the \code{in} vector".

The use of the errors are described in the ADD section on statistics.
Basically, one wants to weight the values in the statistics, so that values with
large measurement errors are weighted less. The driver for this was the
pmReadoutCombine module, specifically the case of flat field combination: when
combining an image that has 40,000 counts and one that has 1,000 counts, I want
the image with 40,000 counts to have a higher weight (it's a better measurement
because there was more light).

[Paul Price]

Closing subsequent to release of SDRS-08, ADD-07.