Re: Top 10 IDL Requests

[Michael Plonski <mplonski(at)aer.com>]

I sent a where-not request to rsinc a few years back and nothing
happened.  I put together a system that processes Gigabytes of satellite
data every day.  It has to take several extra passes through the data
because there is no way to do effecient nested wheres.  Basically, I
want to run a new where on the result of the where-not in order to do
further segmentation on the items not segmented out by the first where
command. I also first asked for user defined map projections probably 6
or 7 years ago.  That never happened either, even when I said, well
PV-Wave has it (or at least claims to).

If fact the only time I ever got RSI to make a change was when I showed
that something in version 5 didn't work the same as version 4 (how the
sign bit is promoted in byte to short to long conversions when they
introduced the concept of unsigned). It might have been 5.2 .vs. 5.1
instead of 5 .v.s. 4.  This seemed to be a high priority for them since
it meant Version 5 wouldn't give the same numerical answer as version 4
in some really limited cases.  It did break some code I was using and
took a while to track down.   

Mike Plonski


"Liam E. Gumley" wrote:
> 
> Craig Markwardt wrote:
> >
> > "Liam E. Gumley" <Liam.Gumley@ssec.wisc.edu> writes:
> > > Michael Plonski wrote:
> > > > 1) Complement of Where - so the same call returns where, and a named
> > > > variable returns where-not
> > >
> > > FUNCTION WHERENOT, TEST, COUNT
> > > return, where(test eq 0, count)
> > > END
> > ...
> > > It requires another 'where' call if you want the where and where-not,
> > > but I'm guessing this functionality isn't needed that often.
> >
> > No, Mr. Plonski, myself, and several others on this news group were
> > asking for the WHERE and its complement in the same function call.  It
> > does come up a fair amount for me, and it can be a big computation
> > expense to do WHERE twice if the arrays are large.
> 
> Well now is the time to ask for this feature in WHERE (while IDL 5.4 is
> still in Beta). Perhaps a COMPLEMENT keyword could be added: I'm not
> that fond of optional arguments.
> 
> I suggest that anybody who wants this feature send email to RSI
> (mailto:support@rsinc.com) with the subject 'Feature Request' asking for
> this functionality to be added to WHERE.
> 
> Cheers,
> Liam.
> http://cimss.ssec.wisc.edu/~gumley