Hello

i have a question regarding the Compiler:-Compile Command in Maple12
under linux i got this error message when trying to compile the example:
> y := proc( x :: float ) 2.3 * x end proc:
> cy := Compiler:-Compile( y):
Error, (in Compiler:-Compile) possible installation problem:
GNU C compiler (gcc) not found in your command search
path (PATH). You will need to restart Maple after ensuring that gcc
is installed and adjusting your PATH environment variable.
>
> cy( 1.1 );
cy(1.1)
but the compiler is installed in /usr/bin and maple knows the path:
> getenv(PATH);

That’s a mantra I need to have drummed into me, and perhaps tattooed on the inside of my car so I’m reminded every morning.  But I keep on making the same mistakes. 

 I seem to think that if I’ve “optimized” my portfolio with a few flashy calculations that I’ve done my due diligence, and the next stop is financial independence.  It’s the black box syndrome – trusting the output of a computer program without truly understanding the real issues.  Most portfolio analyses, for example, hinge on historical data, which of course doesn’t predict the sub-prime blow-up in the US or whether Brazilian coffee growers are on strike.  They’re all backward looking.

 However, in the absence of a neighbourhood scryer, historical analyses are a good indication of how to position a portfolio for the long term.

 Being a geek (however much I strenuously deny it), I tend leverage my tech skills wherever I can.  I wrote the attached worksheet to import stock quotes, including historical data, from Yahoo using the Sockets package.  Simply type in the appropriate NYSE stock tickers into the appropriate text boxes, check the quantities you want to download, and click the big gray button.

 All the stock quotes and historical data can be manipulated on the command-line and can be accessed via command-completion. 

 It then finds the best distribution of stocks in a portfolio by maximizing its Sharpe Ratio (through the Optimization package). 

The Sharpe ratio quantifies how effectively a portfolio of risky assets utilises risk to maximise return.  It’s defined as follows.

 

 

It essentially measures how effectively a portfolio uses risk to maximize return – the higher the ratio the better.  The expected portfolio return is predicted from historic data, the portfolio standard deviation is traditionally used as a proxy for risk, and the risk free return is the return that can be expected from a zero-risk investment (i.e. the interest on US Treasury Bills or the redemption yield on UK gilts).

What I find particularly fascinating is how Maple is now the centre of my technical desktop.  Through the combination of the interface and its math tools, I now use it for everything from the simplest calculations through to making wild guesses about my financial future.  If any of the developers are reading this, I want you to know there’s a lot riding on you...

I have never had this problem in other versions. But in Maple 12, some search topics (sum, add, for instance) are guaranteed to lock it up. In addition, after a short series of HELP searches, the search operation locks up. It sems to be inevitable, search enough times, and it locks up. At the suggestion of Maple staff, I uninstalled and reinstalled Maple 12. It did not help.

I am using maple 10 and saved a worksheet yesterday. Today I tried to open it but it says "There were problems during the loading process. Your worksheet may be incomplete." And parts of my document is gone.

I searched this and found somebody had this same problem back in 2001. But there was no informtion as to how to maybe recover the contents. Any ideas?

Thanks a lot.

Hello,

ich have an economics model considering the effects ot temporary work on the labor market. Under a specific calibration of the model parameters, i arrive at the following "flow" eqautions, that determine the relative magnitude of "regular employment" E, "unemployment" U and the temporary work sector A and T. The flow equations are:

Hi, how we can get the min of two real-valued piecewise continuous functions as another piecewise function. To me Maple responded with min(fn1,fn2), which I dont need. Plz hep.

Ruined your life?  Well, almost.  But now that you’re intrigued with my wild claim, let me explain.

The science of mathematics has a very long heritage.  The language of mathematics, as we recognize it today, is a bit younger – widely credited to François Viète, who introduced the first systematic algebraic notation in the last half of the 16^th Century.

Along the way, over the course of many centuries, the power of mathematics increased steadily, through the contributions of many great men. 

There are two new posts over on the Maplesoft Blog:

Postcards from the road: Part 1 -- On rocket science

By Tom Lee

One of the greatest pleasures of my job is meeting users and learning first hand of their achievements (hopefully with our products). Last week was a particularly eventful week and a distinct highlight was a visit our friends at the Canadian Space Agency (CSA) in Montréal.

One of the greatest pleasures of my job is meeting users and learning first hand of their achievements (hopefully with our products). Last week was a particularly eventful week and a distinct highlight was a visit our friends at the Canadian Space Agency (CSA) in Montréal.

Dear all, I need some help with this program I have. I ran this recursive system only to find that it stopped working at 1.89Gb. Anyone out there knows the problem or maybe there's a better way of writing this program?

Following worse-than-good advice can lead to loss of time and to greater misunderstanding. I have noticed, over the past year, a growing proportion of suboptimal responses and advice on the mapleprimes forums.

There are still many fine responses, but slightly incorrect or inefficient (and sometimes outright wrong) responses seem to have been growing as a proportion of the whole. This is probably natural, as the mapleprimes site grows. But some of the ensuing bad effects of it could be avoided.

Hi, I want to carry out set-theoretic operations on real-line intervals.  For example

> [2,5] intersect [3,7];
 

Is there any package available for this and interval arithmetics?

Thanks.

In ?property > Description it is stated:

A property can be:
...
(2) most types (this includes constant values, for example, 0)

E.g. I can do:

assume(x,1):
about(x);

Originally x, renamed x~:
  is assumed to be: 1

is(x,1);
                                    true

But, I am missing a useful example for such a property.

Besides, I find these properties confusing as 0 and 1 have parent properties entries in the property lattice, but not 2:

This behaviour of 'assume' puzzles me ... 
and it needed some time to locate it
 
  restart; interface(version);

  Classic Worksheet Interface, Maple 12.00, Windows, Apr 10 2008 Build ID 347164

  assume(a::real); 
    #a:='a'; # activating removes the problem
  f0:=x+a; 
    #a:='a'; # that would not help - since is in use?
  assume(0<a);
  f:=collect(f0,x);

     ...

It would be nice to have a link to Recent posts off the main mapleprimes page that guests see (ie. even when not logged in).

It'd be a pity if the only reason that this is not available is just so that page can show how many new (unread by logged-in user) posts there are in each thread.

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