Bessel function differential equation



Hello Barton,

Thank you for the work around.  When I tried to do the same thing, I got:

Maxima encountered a Lisp error:
 
EVAL: too many arguments given to SRATSIMP: (SRATSIMP P X)
Automatically continuing.
To reenable the Lisp debugger set *debugger-hook* to nil.

This is a consistent error I get every time I load a module and then try 
to run something with it.  This would seem to suggest a bug; I am using 
maxima-5.17.1-1.centos4.i386.rpm on a Centos 4.7, i386 box.  Has anyone 
else encountered similar problems?  I am hoping to avoid having to 
compile my own version of Maxima.

Is it suggested that I compile my own version of Maxima?  Thank you for 
your help!


Cheers,
Carl


Barton Willis wrote:
> A work around is to call odelin directly
>
>  (%i5) load(odelin)$
>  (%i6) odelin(x^2*'diff(y,x,2)+x*'diff(y,x)+(a^2*x^2-b^2)*y=0,y,x);
>
>  (%o6) {bessel_j(b,-a*x),bessel_y(b,-a*x)}
>
> I think ode2 is supposed to call odelin automatically; apparently something
> in this
> process is broken. Maybe you could file a bug report.
>
> Barton
>
> -----maxima-bounces at math.utexas.edu wrote: -----
>
>
>   
>> I am trying to solve the following diff eq:
>>
>> x^2*diff(y,x,2)+x*diff(y,x)+(a^2*x^2-b^2)*y=0
>>
>> which should lead to the following solution:
>>
>> y=c1*bessel_j(b, a*x) + c2*bessel_y(b,a*x)
>>
>> If I use ode2 to solve, I get the message "false", meaning it couldn't
>> solve it, and if I use odelin or contrib_ode, I get the message
>>
>> EVAL: too many arguments given to SRATSIMP: (SRATSIMP P X)
>> Automatically continuing.
>> To reenable the Lisp debugger set *debugger-hook* to nil.
>>
>> However, if I ask ode2 to solve:
>>
>> x^2*diff(y,x,2)+x*diff(y,x)+(x^2-1)*y=0
>>
>> I get:
>>
>> y=c1*bessel_j(1,x) + c2*bessel_y(1,x)
>>
>> which is, of course, the correct solution.  Clearly, I am not doing
>> something correctly with the constants a and b.  Might there be someone
>> who could provide me with some insight?  Thank you all for your help!
>>
>>
>> Cheers,
>> Carl
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>>     
>
>
>