I’ve had a quick look, and what I might do is try simple TexMacs under Windows first of all simply as a LyX alternate to get a feel for it, and then if it seems workable, use that when I start writing Finance and Economic Breakdown properly next year and then do a full installation. I have a spare PC right now so I might make that a full Linux base machine (next year) and try with that.

For now I have to get this multi-sectoral stuff finished pronto, so working in what I know will be faster than learning a whole new system and restarting.

Here’s an example that includes TeXmacs display of “live” (algebraic) solutions of simple ODEs using Maxima (which is also available for Windows). It also interfaces direct to “R” which has comprehensive statistical stuff (free clone of “S”) highly relevant to economics and also to Matlab and Octave (free Matlab clone) with adequate numeric ODE solvers as well as to Sage (which itself interfaces to all 3 and SciPy numeric ODE solvers and matrix algebra etc and provides a superior combination environment).

The TeXmacs/Maxima example in 4th screenshot above is pretty similar to what you could get directly with TeXmacs/Sage numeric solutions of ODEs and looks to me pretty clearly superior to your Mathcad example.

Try TeXmacs first, simply as a general powerful scientific wordprocessor vastly superior to LyX et al and later add Sage. Even though Sage would be running on a virtual linux over windows it should still be just as easy and fast for it to communicate with Windows/Cygwin TexMacs as the interface is via network stack on “localhost” (and can also be made remotely accessible if you want).

BTW QtOctave GUI interface for Octave similar to the Matlab desktop is also available for Windows.

Likewise of course the normal “Notebook” browser interface to Sage is also via network to Firefox browser so despite the virtual linux for Sage itself you would be working entirely in your normal Windows environment apart from the initial hassles of setting it up.

The model starts with a single sector and then expands to multiple, but looking at the paper I didn’t document all the steps to the latter as well as I might have (it’s more a book length thing in that case). So the PDF should help. I’ll amend the post and put a link on my research page.

(Still confused by filenames)

(No error messages – consistent with site simply being overloaded – I have noticed it being very slow generally. You may need more bandwidth from hosting ISP generally due to increased traffic.)

Anyway, email them as well as fixing here if necessary and I’ll certainly be interested. Still no guarantee on how long it will take, so don’t wait to checkout Sage for yourself – but I was already thinking of using your earlier model for trying out Sage .

Here’s an excellent overview (5pp) article for SIAM Review by reviewer with a 20 year investment in Mathematica (will use only Sage from now on).

Here’s a live online calculus “notebook” showing it can display nicely formatted equations like Mathcad. Use firefox browser, not Internet Explorer in case of problems. You can use these notebooks as a working environment through your browser locally (automatically installed on private webserver) or remotely via free account at above public server or to your own server – eg can use while travelling with iPhone.

It can also “weave” live displays of equations and plots of solutions directly into LaTeX papers (like “sweave” for “S” or “R” statistical calculations and plots).

For linux users, proceed to download as soon as you get intrigued by above.

For windows users the normal download is even larger and less convenient (as always). You may want to choose one of the two even bigger huge downloads (1.5GB) instead so you have LaTeX and lots of other stuff that you will end up needing on a virtual linux that runs under windows. Read the readme files for normal and 3 experimental variants carefully before choosing. Assuming you have 2GB RAM and modern CPU with hardware virtualization you may want the specific one that requires that.

Meanwhile windows users could play with it before choosing by working through the tutorial in .pdf docs via an online account as above.

Key example is the one I mentioned in passing – vintages of fixed capital investment. The “anti-cyclic” stimulus to investment during depressed periods turns up later as “pro-cyclic” overcapacity.

A well known proposition connected with theory of value, that the unity of exchange value and use value is only established by realization in actual exchange and systemically enforced only through fluctuations and crises. Sadly foreign to Keynesians etc who apparantly believe that a dynamic system can be controlled when it cannot even be observed and predicted, contrary to long established results in control theory etc.

If governments could respond instantly, the inherent dynamics would still be there. “Perfect foresight” beloved in the propaganda is provably equivalent to “perfect planning” and inherently contradicts the essential nature of a “market” economy.

“Perfect planning” is of course equally illusory but unavoidable uncertainties, including things we don’t know that we don’t know, would only result in “inefficiencies” and “mistakes” when the mechanism for disproportions is not crisis but simply reallocation.

Am stressing this because the models need far more attention to the disproportions in the “real” economy that are the underlying cause, not merely the consequence of financial disproportions.

eg Seems obvious that sub-prime mortages not merely a financial mistake, but a consequence of overcapacity in housing production and inability to house people who cannot afford because their incomes have nothing to do with the glut of investment funds available from exploiting them.

“Solutions” like tighter regulation so people don’t borrow for homes they cannot afford simply mean earlier outbreak of the underlying problem – ie massive layoffs in construction and poor housing.

Not sure why I thought I had scanned the Mathcad docs. I haven’t (still waiting for bit torrent . Must have been one of the others (I have been getting eye-glazed trying to get up to speed with this stuff). I would however assume that Mathcad includes the solvers available in other packages (and adds a much nicer WYSIWG interface etc). The underlying solver “codes” are common.

Also re SBML for “model changes with thresholds” I should have included the term “events” for clarity. See:

Hybrid Systems and SloppyCell

Re #16 Steve,

Yes, we’re both referring to time lags. Don’t take my word for it as I’m definately NOT up to speed on this stuff. But although the “trick” you use for delays is widely used in systems engineering and handles exponential growth I’m pretty sure economic models will need more than that (eg for vintages of fixed capital which have a lot to do with business cycles). Do check for yourself re the additional complexities of Delay Differential Equations. I’m also pretty sure this is important for your work (and might be relevant to selection of software). See also above links re available solvers.