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« Big Climate likes to silence inconvenient journalists | Main | Climate scientist Jim Salinger stoops to lowest debate level ever »

Comments

CM

If you weren't a skeptic Falafulu, this is where Ian would tell you that you were being pedantic.

>>>If you work as a climate scientist somewhere, then you deserved to be sacked (same as Salinger), because it is obvious that don't know the difference between ground-breaking theories/researches and a prostitute.<<<

Who said I work as a climate scientist anywhere? Are you on drugs?

Falafulu Fisi

CM said...
Ian would tell you that you were being pedantic.

Perhaps that's true, but really I am a technologist, where as climate scientists they are not. I am employable in any technology field really (as I have a tech startup that I am working on), but in comparison to someone like Jim Salinger, well he hasn't figured out yet where is the next job is going to come from apart perhaps, he can team up with our moon weather prediction guy such as Ken Ring.

I am sure that Mr. Ring will give Jim Salinger a job at his West Auckland moon weather prediction center. This is the main difference between being pedantic and being a technologist.

CM

>>>Please, show us your code
Filed under: Climate ScienceRC Forumskeptics— rasmus @ 17 December 2009
The 1991 Science paper by Friis-Christensen & Lassen, work by Henrik Svensmark (Physical Review Letters), and calculations done by Scafetta & West (in the journals Geophysical Research Letters, Journal of Geophysical Research, and Physics Today) have inspired the idea that the recent warming is due to changes in the sun, rather than greenhouse gases.

We have discussed these papers before here on RealClimate (here, here, and here), and I think it’s fair to say that these studies have been fairly influential one way or the other. But has anybody ever seen the details of the methods used, or the data? I believe that a full disclosure of their codes and data would really boost the confidence in their work, if they were sound. So if they believe so strongly that their work is solid, why not more transparency?


There is a recent story in the British paper The Independent, where Friis-Christensen and Svensmark responded to the criticism forwarded by Peter Laut (here). All this would perhaps be unnecessary if they had disclosed their codes and data.

Gavin and I published a paper in Journal of Geophysical Research, where we tested the general approach used by Scafetta & West, and tried to repeat their analysis. We were up-front about our lack of success in a 100% replication of their work, but we argue that the any pronounced effect – as claimed by Scafetta & West – should be detectable even if the set-up is not 100% identical.

However, Scafetta does not accept our analysis and has criticized me for lacking knowledge about wavelet analysis – he tells me to read the text books. So I asked him to post his code openly on the Internet so that others could repeat our test with their code. That should settle our controversy.

After repeated requests, he told me that he doesn’t really understand why I’m not able to write my own program to reproduce the calculations (actually, I did in the paper together with Gavin, but Scafetta wouldn’t accept our analysis), and keeps insulting me by telling me to take a course on wavelet analysis. Furthermore, he stated that there “are several other and even more serious problems” in our work. I figure then that the easiest way to get to the bottom of this issue it to repeat our tests with his code.

A replication in general doesn’t require full disclosure of source code because the description in the paper should be sufficient, though in this case it clearly wasn’t. So to both save having us do it again and perhaps miss some other little detail – in addition to using an algorithm that Scafetta is happy with – it’s worth getting the code with which to validate our efforts.

It should be a common courtesy to provide methods requested by other scientists in order to speedily get to the essence of the issue, and not to waste time with the minutiae of which year is picked to end the analysis.

The reason why Gavin and I were not able to repeat Scafetta’s analysis in exact details is that his papers didn’t disclose all the necessary details. The first point he raised was that we used periodic instead of reflection boundaries. The fact that the paper referred to the expression ‘1/2 A sin (2 pi t)’ to describe the temperatures or solar forcing would normally suggest that they used periodic rather than reflection boundaries. There was no information in the paper about reflection boundary. But this is no big deal, as we have subsequently repeated the analysis with reflection boundary, and that doesn’t alter our conclusions.

After further communication, we found out that Scafetta re-sampled the data in such a way that the center of the wavelet band pass filter was located exactly on the 11 and 22 year solar cycles, which were the frequencies of interest. He also informed me that a reasonable choice of the year when the reflection boudary was made should be the year 2002-3 when the sun experienced a maximum for both the 11 and 22 year cycles. This information was not provided in the papers.

I’m no psychic, so I couldn’t have guessed that all this was needed to reproduce his result. But since Scafetta has lost faith in my ability to repeat his work, I think it’s even a greater reason to disclose his code so that others can have a go.

For the record, we did not just use wavelets to filter the data – we obtained the same conclusion with an ordinary band-pass filter.<<<

http://www.realclimate.org/index.php/archives/2009/12/please-show-us-your-code/

Crap. I guess that’s the end of skeptics and deniers saying “it’s the sun”. If you don’t release 100% of your data and code, it’s *obviously* fraudulent.

Falafulu Fisi

Wavelet is a statistical method and not physics. Digital filtering methods (used in signal processing) are also statistical methods and not physics.

I use digital signal processing methods and wavelet a lot and they're good in non-adaptive complex system applications. In climate system modeling (adaptive complex system), it use has limited success, but they're there as useful methods to use. Useful doesn't establish causation, and how many times that I have to pointed out to you.

The particular wavelet that I implemented (commercial software) was based on the following model described in the following paper, which is a hybrid of ANN (artificial neural network) and wavelet.

Prediction Model of Stock Market Returns Based on Wavelet Neural Network

Guess what. Our complex wavelet neural network model was just above average in its performance. WHY? Because it is only a useful algorithm/model, but really it doesn't give or tell us, the true mechanics of what drives the financial markets. Had we discovered the true mechanics (causes & effects) of what drive the markets, we wouldn't be bothered to implement the wavelet neural network which we hoped that was going to give our users superior returns in their trading.

That's the whole point here. Be it wavelet, high-pass, band-pass, low-pass or any other types of signal processing filters used in time-series analysis (climate, finance, sales data, etc,...), they don't establish the causation, none whatsoever. The debate about AGW is its cause and not its correlation to other climate observables, regardless of the mathematics being used and you should have known or understood that by now.

CM said...
Crap. I guess that’s the end of skeptics and deniers saying “it’s the sun”.

It wasn't the solely about the "sun", it's about of what we don't know. The sun was proposed as a likely cause, but it could be something that we really don't know. Do you follow me or not? It seems that you don't.

Let's go back to an a favourite example of mine from Quantum Mechanics, which is its epitome, the :

Double-Slit Experiment

The math says that material object (electrons in this case) do traverse through different separated points in space at once, ie, the particle goes thru the 2 holes at once. The size of the object is irrelevant, since the experiment has been carried out with more massive larger particles (Bose-Einstein condensate super-atoms). Experimentally, it has never been proven that in fact that the particle went thru the 2 holes at once, because once a detector is put near one of the holes to tell us which hole that each particle passes thru, it mean that each particle only went thru one of them (either A or B), but not both. We rely on the math. The math says that it went thru both, in order for the interference pattern to be formed when the particles are shoot one at a time.

So, mathematically to speak, anything can be at 2 places simultaneously. Realistically (ie, philosophically & metaphysically), we can dismiss that possibility and say that we just don't know. The cause is unknown to us at this stage.

Here is a consensus amongst physicists which the majority agree that the particle indeed goes thru hole A and B simultaneously, simply because the math say so, if we're to retain our sanity, that interpretation must be dismissed as fantasy, irrelevant if there is a consensus about the cause.

The Interpretation of Quantum Mechanics: Many Worlds or Many Words?

This is the position of most skeptics. We just don't know yet. It is premature to say that global warming is man-made.

You seem to be one dimensional in your argument here CM, since you think that every skeptic must believe that it is the sun. Prof Lindzen (top skeptic climatologist) is not in this group and a whole lot others.

Listen, you really look like an idiot here with your comment for the sake of it and not only that, you're one dimensional.

CM

>>>You seem to be one dimensional in your argument here CM, since you think that every skeptic must believe that it is the sun.<<<

Yeah but that's not what I said now is it. I hope you don't misrepresent this much in your professional life.

New Balance Sneakers

The more you fight something, the more anxious you become ---the more you're involved in a bad pattern, the more difficult it is to escape. Do you understand?

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