[R] Fw: Multiple Integrals

2015-08-30 Thread Shant Ch via R-help
Thank you very much to all for all your responses.

@Dr. Winsemius, E[f(X)] =f(E(X)) if f is convex. Now we know |x| is convex 
function, so clearly in this scenario if we compute the expectation of the 
((X1+X2+X3)/3-X4) and then take the absolute, then, we will get a lower bound 
of the expectation I want to find. 

  On Saturday, August 29, 2015 7:24 PM, David Winsemius 
dwinsem...@comcast.net wrote:
   

 
On Aug 29, 2015, at 11:35 AM, Shant Ch via R-help wrote:

 Hello Dr. Berry,
 
 I know the theoretical side but note we are not talking about expectation of 
 sums rather expectation of ABSOLUTE value of the function 
 (X1/3+X2/3+X3/3-X4), i.e. E|X1/3+X2/3+X3/3-X4|  , I don't think this can be 
 handled for log normal distribution by integrals by hand.
 

To Shnant Ch;

I admit to puzzlement (being a humble country doctor). Can you explain why 
there should be a difference between the absolute value of an expectation for a 
sum of values from a function, in this case dlnorm,  that is positive definite 
versus an expectation simply of the sum of such values?

-- 

David Winsemius
Alameda, CA, USA


   
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Re: [R] Fw: Multiple Integrals

2015-08-30 Thread David Winsemius

On Aug 30, 2015, at 8:41 AM, Shant Ch via R-help wrote:

 Thank you very much to all for all your responses.
 
 @Dr. Winsemius, E[f(X)] =f(E(X)) if f is convex. Now we know |x| is convex 
 function, so clearly in this scenario if we compute the expectation of the 
 ((X1+X2+X3)/3-X4) and then take the absolute, then, we will get a lower bound 
 of the expectation I want to find. 
 

I understood the error in my thinking when Jeff Newmiller pointed out the minus 
sign that I had missed.

Thanks;
David.


  On Saturday, August 29, 2015 7:24 PM, David Winsemius 
 dwinsem...@comcast.net wrote:
 
 
 
 On Aug 29, 2015, at 11:35 AM, Shant Ch via R-help wrote:
 
 Hello Dr. Berry,
 
 I know the theoretical side but note we are not talking about expectation of 
 sums rather expectation of ABSOLUTE value of the function 
 (X1/3+X2/3+X3/3-X4), i.e. E|X1/3+X2/3+X3/3-X4|  , I don't think this can be 
 handled for log normal distribution by integrals by hand.
 
 
 To Shnant Ch;
 
 I admit to puzzlement (being a humble country doctor). Can you explain why 
 there should be a difference between the absolute value of an expectation for 
 a sum of values from a function, in this case dlnorm,  that is positive 
 definite versus an expectation simply of the sum of such values?
 
 -- 
 
 David Winsemius
 Alameda, CA, USA
 
 
 
   [[alternative HTML version deleted]]
 
 __
 R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
 https://stat.ethz.ch/mailman/listinfo/r-help
 PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
 and provide commented, minimal, self-contained, reproducible code.

David Winsemius
Alameda, CA, USA

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R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see
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