## 444 Reputation

15 years, 225 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.

## indeed...

You are right and I was wrong.

Thanks for clarification.

## indeed...

You are right and I was wrong.

Thanks for clarification.

## Thanks...

Both comments were very useful to me.

## Thanks...

Both comments were very useful to me.

## i c...

I see your point. Thanks for clarification on this.

## i c...

I see your point. Thanks for clarification on this.

## sure?...

Are you sure your way is doing what I intended?

Compare EY (your suggestion) and EG (computation of expected utility without using 'ExpectedValue'):

with(Statistics):
assume(mu::real,sigma>0);
X:=RandomVariable(Normal(mu,sigma)):
Y:=RandomVariable(Distribution(PDF=subs(f=unapply(PDF(X,T),T),t->(1-exp(-phi*t))*f(t)))): #I used a specific function u(t)
EY:=ExpectedValue(Y);

EG:=int(1/(sqrt(2*Pi)*sigma)*exp(-(t-mu)^2/(2*sigma^2))*(1-exp(-phi*t)),t=-infinity..infinity);

I am not sure how to show efficiently with Maple, if those two expressions are different, but evaluating at specific points outputs different values though.

## sure?...

Are you sure your way is doing what I intended?

Compare EY (your suggestion) and EG (computation of expected utility without using 'ExpectedValue'):

with(Statistics):
assume(mu::real,sigma>0);
X:=RandomVariable(Normal(mu,sigma)):
Y:=RandomVariable(Distribution(PDF=subs(f=unapply(PDF(X,T),T),t->(1-exp(-phi*t))*f(t)))): #I used a specific function u(t)
EY:=ExpectedValue(Y);

EG:=int(1/(sqrt(2*Pi)*sigma)*exp(-(t-mu)^2/(2*sigma^2))*(1-exp(-phi*t)),t=-infinity..infinity);

I am not sure how to show efficiently with Maple, if those two expressions are different, but evaluating at specific points outputs different values though.

## learned something new...

Thanks acer,

I learned something new. In fact I didn´t know, that the Digits environment variable controls the working precision and that the effect of round-off error could be that significant.

So may I also manipulate the working precision of the 'Explore' option by setting 'Digits' to another value (say 20) or is there another way of minimizing the round-off error effects when using 'Explore'?

## learned something new...

Thanks acer,

I learned something new. In fact I didn´t know, that the Digits environment variable controls the working precision and that the effect of round-off error could be that significant.

So may I also manipulate the working precision of the 'Explore' option by setting 'Digits' to another value (say 20) or is there another way of minimizing the round-off error effects when using 'Explore'?

## Solved the problem...

Indeed I thought that this assumption might help.

Anyway, your suggestion of using 1+X1 instead of X1 helped a lot. This is compatible with ln(x) and yields no zero values.

## Solved the problem...

Indeed I thought that this assumption might help.

Anyway, your suggestion of using 1+X1 instead of X1 helped a lot. This is compatible with ln(x) and yields no zero values.

## Didn´t Maple account for assumptions?...

Well, of course you are right for the usual domain of x.

Anyway by additionally using assumpions, I tried to limit the domain of x to positive integers.

If I did it the wrong way I may ask you to correct me and tell me how to do better.

## Didn´t Maple account for assumptions?...

Well, of course you are right for the usual domain of x.

Anyway by additionally using assumpions, I tried to limit the domain of x to positive integers.

If I did it the wrong way I may ask you to correct me and tell me how to do better.

## Thanks...

Until now I always had a constant "feeling" that there must be a difference between assume and assuming.

Now I know at least one aspect of their heterogeneousness.

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