Apologies for the mailbox clutter, but I've answered my own question... $PDL::undefval = -999;
is the easy solution!!! Can $PDL::undefval be set to BAD somehow?? Trevor. ----- Original Message ----- From: Trevor Carey-Smith <[EMAIL PROTECTED]> Date: Wednesday, May 23, 2007 4:15 pm Subject: PDL and databases To: perldl list <[email protected]> > Hi, > > I'm trying to extract data from an oracle database directly into > piddles. The method below suggested by Doug works, except when > there are NULL values in the database. These all end up as > zeroes in the piddle. Does anyone know of a workaround to > this... perhaps setting the value to bad? > > Regards, > > Trevor. > > > ----- Original Message ----- > > > From: Doug Hunt <[EMAIL PROTECTED]> > > > Date: Tuesday, July 4, 2006 10:17 am > > > Subject: Re: Fw: PDL Getting Started book Re: [Perldl] IDL thing > > > To: [EMAIL PROTECTED] > > > Cc: perldl list <[email protected]> > > > > > > > Hi Celia: > > > > > > > > In many cases its easy to get SQL database info into a 2D PDL. > > > > > > > > We use postgres, so I often say something like: > > > > > > > > my $db = "dbi:Pg:dbname=$dbname;host=$dbhost"; > > > > my $dbh = DBI->connect($db); > > > > die "Cannot connect to database = $dbname, dbhost = $dbhost" > > > > unless (defined($dbh)); > > > > > > > > my $sql = "select id, value1, value2 from table1 where ..."; > > > > > > > > my $p = pdl ( $dbh->selectall_arrayref($sql) ); > > > > > > > > This works provided all the selected values are numeric. > > > > > > > > Regards, > > > > > > > > Doug > > > > > > > > [EMAIL PROTECTED] > > > > Software Engineer III > > > > UCAR - COSMIC, Tel. (303) 497-2611 > > > > > > > > On Wed, 28 Jun 2006, [EMAIL PROTECTED] wrote: > > > > > > > > > > > > > > I sort of got into PDL because it sounded a very interesting > > > > way to do data > > > > > manipulation. But I found it very hard to get going. I > > > > also found it was > > > > > hard to find stuff unless you exactly knew what you where > > > > doing and what it > > > > > was named. It was also very hard to find example > > > > scripts. I love example > > > > > scripts it is how I learn stuff. > > > > > > > > > > My problem was that most of my files where in comma > delimited > > > > format or > > > > > from relational databases ( which I used a dbi modules to > > > > get). I really > > > > > wanted example of how to get data from the following sources > > > > into PDL. But > > > > > I found it hard to find resources and also ran out of > > > > time. So I didn't > > > > > end up doing it. > > > > > > > > > > Celia > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Donald Jackson > > > > > <[EMAIL PROTECTED] > > > > > > ms.com> To > > > > > > > > > > 28/06/2006 > 12:43 cc > > > > > AM > > > > > > Subject > > > > > Re: PDL Getting > Started book Re: > > > > > [Perldl] IDL thing > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > As a newbie user, I can attest to the need- the POD is > pretty > > > > good, but > > > > > it's like a dictionary: you need to know what to look for in > > > > order to > > > > > find it! > > > > > > > > > > I'd happily volunteer as a guinea pig for testing drafts on. > > > > > > > > > > Don Jackson > > > > > > > > > > Xavier Calbet wrote: > > > > > > > > > >> If you all agree, we could start writing > > > > >> a simple introductory PDL book... > > > > >> > > > > >> > > > > > > > > > > _______________________________________________ > > > > > Perldl mailing list > > > > > [email protected] > > > > > http://mailman.jach.hawaii.edu/mailman/listinfo/perldl > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > _______________________________________________ > > > > > Perldl mailing list > > > > > [email protected] > > > > > http://mailman.jach.hawaii.edu/mailman/listinfo/perldl > > > > > > > > > > > > > _______________________________________________ > > > > Perldl mailing list > > > > [email protected] > > > > http://mailman.jach.hawaii.edu/mailman/listinfo/perldl > > > > > _______________________________________________ Perldl mailing list [email protected] http://mailman.jach.hawaii.edu/mailman/listinfo/perldl
