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Topic: Regarding Bessel function
Replies: 7   Last Post: Dec 24, 2013 3:12 PM

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Neethu

Posts: 7
Registered: 12/22/13
Re: Regarding Bessel function
Posted: Dec 22, 2013 11:47 PM
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"Nasser M. Abbasi" wrote in message <l96q5l$3gc$1@speranza.aioe.org>...
> On 12/22/2013 3:40 AM, Neethu wrote:
> > "Nasser M. Abbasi" wrote in message <l96ane$rcf$1@speranza.aioe.org>...
> >> On 12/21/2013 11:16 PM, Neethu wrote:
> >>> Can anyone tell how to calculate zeroth order modified bessel function of large real numbers?
> >>> It returns infinity as the result when iam using besseli(0,700)
> >>>

> >>
> >>
> >> EDU>> besseli(0,700)
> >>
> >> ans =
> >>
> >> 1.5296e+302
> >>
> >> What did you want Matlab to return?
> >>
> >> http://www.mathworks.com/help/matlab/ref/besseli.html
> >> http://www.efunda.com/math/bessel/bessel.cfm
> >>
> >>

>
>

> >> Sir, please try besseli(0,720);
> > for me it returns infinity(inf as the result)
> >>
>
> You are correct. besseli(0,720) gave infinity on Matlab. Matlab
> double precision was not large enough to represent the
> result. so it gave infinity. So here is Mathematica' answe
>
> BesselI[0, 720.]
> 7.3172221224922304538512914095434134621329`15.954589770191005*^310
>
> Is this what you looking for? mupad could not evaluate it either:
>
> EDU>> evalin(symengine,'besselI(0,720.)')
> Error using mupadengine/evalin (line 101)
> MuPAD error: Error: Invalid input. 'expression' is expected. [line 1, col 15]
>
> Expression is valid. I think mupad wants exact values only, and
> then it does not evaluate it:
>
> EDU>> evalin(symengine,'besselI(0,720)')
> besseli(0, 720)
>
> Why are do you need such large numbers?
>
> --Nasser
>
> Sir, i need to calculate the log likelihood function for Non local means maximum likelihood algorithm .In that i need to calculate the bessel function of values.But when the values are greater than 700,it returns infinity values.Can you please suggest any way to overcome this


>
>




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