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26 Nov 2009
Author: Graeme Klass
For those that have an interest in the code of the recently hacked emails and documents from the Hadley Centre, I have written a little program to automatically extract comments from the source code and text from “readme” text files*. This makes it a little easier to search through code comments.
You can download this file here.
What I discovered is this (documents\harris-tree\briffa_sep98_e.pro):
; PLOTS ‘ALL’ REGION MXD timeseries from age banded and from huge
; standardised datasets.
; Reads Harry’s regional timeseries and outputs the 1600-1992 por
; with missing values set appropriately. Uses mxd, and just the
; “all band” timeseries
;****** APPLIES A VERY ARTIFICIAL CORRECTION FOR DECLINE*********
yrloc=[1400,findgen(19)*5.+1904]
valadj=[0.,0.,0.,0.,0.,-0.1,-0.25,-0.3,0.,-0.1,0.3,0.8,1.2,1.7,2.5,2.6,2.6,$
2.6,2.6,2.6]*0.75 ; fudge factor
Later in the code:
;
; APPLY ARTIFICIAL CORRECTION
;
yearlyadj=interpol(valadj,yrloc,x)
densall=densall+yearlyadj
The fudge factor above does not seem to have a basis in any physical reality. I have done many computer models previously and I recognise that this is a classic example of the programmer trying to massage the data to their needs. What this code does is apply a rudimentary filter to the data. What effect this code actually has is unknown at the present. I am still analysing the code to try to get some sort of filter coefficients so that we can plot the frequency response of these filters to get a better understanding of what is actually going on here.
Watts Up With That has a list of source code comments describing the need to “avoid the decline”.
*Postnote about the program:
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