Article

2009-12-09 -Signs, Portents, and the Weather-

Archived material is restricted to Rantburg regulars and members. If you need access email fred.pruitt=at=gmail.com with your nick to be added to the members list. There is no charge to join Rantburg as a member.

Posted by Mercutio 2009-12-09 16:33|| || Front Page|| [2 views ] Top

#1 Unlike the author of that post (Robert Greiner), I've programmed IDL before.

(Well, mostly I've fixed IDL code others have written, because IDL is not backwards or forwards compatible, and breaks if you give it a hard look, but that's beside the point.)

It doesn't really help me with this, but I can say that anyway.

I can't figure out what he's saying here. The code section he's talking about has 1) an array of years, and 2) a matching array of "adjustments". The interpol() function just sticks more datapoints in between those specified by those arrays.

Now, 19 of the 20 elements in the yrloc array are the years 1904 to 1994. Given those are five-year increments, it's hard to see why they'd want to interpolate between them, to get a finer grid. (I suppose it could also be giving a coarser grid, depending on the content of timey, which is not given at the link.)

But, oopsie!, the first element in yrloc is the year 1400. So the purpose of the interpol call (as far as I can tell) is to re-grid the result so that it looks as if you have more data points between the years 1400 and 1904 than you really do.

Now, the values for valadj from 1400 to 1919 are all zero. If your plot just ran from 1904 to 1994, the rise wouldn't be as spectacular as it is with 500 years of zeros to the left. This is a bit shady, but hardly earth-shattering.

The real question here is the origin of the values in valadj, which the comments seem to suggest is "very artifical". Greiner mentions an array of valid temperature measurements, and the code might have one, but he hasn't presented it. (I kind of think he has mistaken yrloc for temps, when they are clearly years. I believe that the resultant yearlyadj is meant to be applied to something else, which Greiner doesn't present.)

I do not believe there is a smoking gun here, just a misfire. Now if you'll excuse me, it's my day off, and this is entirely too much like work.

Posted by Angie Schultz 2009-12-09 19:44|| 2009-12-09 19:44|| Front Page Top

23:55 JosephMendiola
23:48 JosephMendiola
23:44 JosephMendiola
23:40 USN, Ret.
23:28 USN, Ret.
23:27 KBK
23:17 JosephMendiola
23:09 JosephMendiola
22:53 JosephMendiola
22:44 JosephMendiola
22:35 Bright Pebbles
22:32 Bright Pebbles
22:16 Iblis
22:10 Pappy
22:08 DMFD
21:50 JosephMendiola
21:44 rn
21:42 eLarson
21:41 Skunky Glins****
21:40 rn
21:34 JosephMendiola
21:29 JosephMendiola
21:23 JosephMendiola
21:21 JosephMendiola