Enhanced Laplace transforms and desolve for Maxima
Subject: Enhanced Laplace transforms and desolve for Maxima
From: Mark H Weaver
Date: Sat, 23 Apr 2011 17:24:16 -0400
razif razali <razif66 at gmail.com> writes:
> I have try your patch but it failed in 64bit architecture but
> I?successfully?patch it and run it in 32bit ubuntu10.10. by using your
> patch I simply paste my code in maxima,
[...]
> and your patch help me get the function for f_12_1(s) till f_12_7(s)
> ---------( f_n_k(s) )----------||
>
> this patch also true until f_16_9 only. when i try to run for f_18_10
> i got ' ilt ' result again..below is the code that give ' ilt ' result
[...]
> so what should I do if i want to solve this problem until hundreds ' k ' ?
desoln uses symbolic methods only, specifically by means of the Laplace
transform. Such large systems of differential equations are beyond its
capabilities. To analyze such systems, I think you will have to use
numerical methods.
Best,
Mark
> ----------------------
> load(desoln);
> load(laplac);
> load(hstep);
> load(pwilt);
> load(abs_integrate);
>
> f[n,k] := concat('f_,n,"_",k)(s)$?
> df[n,k] :=?
> ? if n=0 then 0?
> ? else 'diff(f[2*n,k],s)=%psi*((k-1)*sqrt(n-k+2)*f[2*n,k-1]-k*sqrt(n-k+1)*f[2*n,k+1])$?
>
> atvalue(f_18_2(s),s=0,0)$?
> atvalue(f_18_3(s),s=0,0)$?
> atvalue(f_18_4(s),s=0,0)$?
> atvalue(f_18_5(s),s=0,0)$?
> atvalue(f_18_6(s),s=0,0)$?
> atvalue(f_18_7(s),s=0,0)$
> atvalue(f_18_8(s),s=0,0)$
> atvalue(f_18_9(s),s=0,0)$
> atvalue(f_18_10(s),s=0,0)$
>
> makelist( df[9,k],k,1,10);?
>
> desolve(%, makelist(f[18,k],k,1,10) );?
> --------------------------------------------------------------------
>
> so what should I do if i want to solve this problem until hundreds ' k ' ?