afeddersen

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11 years, 62 days
I study psychology and economics with a very quantitative approach to each. I specialised on statistical methods, quantitative diagnostics, portfoio analysis and econometrics. Furthermore I am interested (and above that theoretically and empirlcally involved) in poker, chess and performing arts.

MaplePrimes Activity


These are questions asked by afeddersen

Is Maple able to recognize Excel sheets, or maybe other data structures to which I can export Excel tables and have them represented as Arrays or tables or anything else in Maple?

E.g. I have the following Array:

A:=Array(1..3,1..5,[[11,12,13,14,15],[21,22,23,24,25],[31,32,33,34,35]]);

Now I´d like to shuffle the rows of that Array randomly.

How may I do that most efficiently?
 

I tried to do a Monte Carlo simulation with the Shuffle command from the Statistics package.

Unfortunately the distribution of the random sample differs significantly from the expected distribution even for large n.

Here is what I did:

I tried the following:

restart;
with(Statistics):
Y9 := RandomVariable(LogNormal(a, b)):
assume(a::real, 0 < b):
c9:=solve({mu = Mean(Y9), sigma^2 = Variance(Y9)},{a,b}, UseAssumptions);

 

And received the following warning:

Warning, solve may not respect assumed property 'real' on 'a'.

 

How do I force Maple to account for property 'real' on 'a'?
 

I want to solve several systems of equations and force Maple to account for the assumptions which were made for the used parameters.

For example I tried the following:

restart;
with(Statistics):
Y1 := RandomVariable(Beta(nu, omega)):
assume(0 < nu, 0 < omega):
c1:=solve({mu = Mean(Y1), sigma^2 = Variance(Y1)},{nu,omega}, UseAssumptions);

Now the problem is, that UseAssumptions makes a distinction of cases, even if -like in this case- the results do not differ from each other.

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