Re: [Maxima-discuss] bind stack overflow in loop

[Gunter K. <gu...@pe...>]

Bind stack overflow normally indicates that you are using a recursive function that your lisp didn't convert into a non-recursive loop or that you are trying to handle numbers with thousands of digits...

On 16. August 2014 23:36:00 MESZ, Edwin Woollett <woo...@ch...> wrote:
>I am trying to understand what is causing a lisp
>error "bind stack overflow" in a simple loop, in which
>the only "dangerous" thing I am doing is storing
>values in a one dimensional array. (see code below).
>
>Here is the maxima session (windows xp)
>---------------------------------------------------------------------
>Maxima 5.31.2 http://maxima.sourceforge.net
>using Lisp GNU Common Lisp (GCL) GCL 2.6.8 (a.k.a. GCL)
>
>
>(%i1) load(poisson3);
>(%o1) "c:/k3/poisson3.mac"
>(%i2) arrays;
>(%o2) []
>(%i3) outL : poisson3(25,0.002,0.95,5)$
> array phiL defined
>  r       exact             diff
> start numerov loop
>  2001  2002  2003  2004  2005
>Maxima encountered a Lisp error:
>
> Error in PROGN [or a callee]: Bind stack overflow.
>
>Automatically continuing.
>To enable the Lisp debugger set *debugger-hook* to nil.
>(%i4) arrays;
>(%o4) [phiL]
>(%i5) for j:10500 thru 10494 step -1 do print(phiL[j])$
>0.95
>0.95
>0.95
>0.95
>0.95
>0.95
>0.0
>(%i6) phiL[10500];
>(%o6) 0.95
>(%i7) fpprintprec;
>(%o7) 8
>(%i8) phiL[12500];
>(%o8) 0.95
>(%i9)
>=================================================
>and here is the code file poisson3.mac
>
>/*   poisson3(rmax,h,frac,rprint)  for inward integration of poisson's
>   equation without correction from r = rmax to r = 0 with step size h.
>If frac > 0, uses frac times exact solution to get the first two points
>             at rmax and rmax-h; if frac < 0 uses phi = 1 at first two 
>points.
>   The (dimensionless) charge density is taken to be exp(-r)/8/%pi.
>Values of phi internally are kept in the array phiL; declared arrays
>are
>          global objects until removed from memory using remarray.
>  The output is a list [rrL, phiL_list] in which rrL and phiL_list are 
>lists
>         created using makelist.
>At intervals rprint, values of r, exact, and diff_phi are printed to
>the 
>screen
>          using the formated print function printf.
>
>this version has debug printouts since lisp error "bind stack overflow"
>
>occurs
>  when j = 2005.
>*/
>
>
>
>poisson3(rmax,h,frac, rprint) :=
>block([phi_m,phi_z,phi_p,Sm,Sz,Sp, fac, phiL_list, num,
>             rrL,rr,exact, diff_phi, nprint, nstep,  numer],numer:true,
>    local(phi_exact,S),
>    phi_exact(r) :=  1 - (r+2)*exp(-r)/2,
> S(r) := -r*exp(-r)/2,
>
> if frac < 0 then (
>       phi_p : 1,
>    phi_z : 1)
> else (
>      phi_p : frac*phi_exact(rmax),
>      phi_z : frac*phi_exact(rmax - h)),
>
> Sp : S(rmax),
> Sz : S(rmax - h),
> fac : h^2/(12),
> num :  round (rmax/h),   /* total number of steps to take */
> /*  create an array with num+1 elements, array indexing starts with 0,
>        phiL[0] = phi(r=0), phiL[n] = phi(r=n*h), phiL[num] = phi(rmax)
>         phiL holds all phi values    */
>array(phiL, flonum,  num + 1),             /* floating point number
>array 
>*/
> print(" array phiL defined "),
> phiL[num] : phi_p,                     /*   phi( r = rmax )  */
> phiL[num - 1] : phi_z,                 /*  phi(r = rmax - h)  */
>
> nprint : round(rprint/h),                /* number of steps between 
>printing  */
>nstep : 2,                                   /*  current value of nstep
>*/
>    printf(true,"~&~2t~a~10t~a~28t~a","r","exact","diff"),
> print(" start numerov loop "),
>
> for j:2 thru num do (
>      if j > 2000 then printf(true,"  ~d", j),
> rr : rmax - j*h,                       /* for j=2, rr = rmax - 2*h  */
>   Sm : S(rr),
>   phi_m : 2*phi_z - phi_p + fac*(Sm + 10*Sz + Sp),
>   phiL[num - j] : phi_m,
>   if  is(equal(nstep,nprint)) then (
>       exact : phi_exact(rr),
>            diff_phi : exact - phi_m,
>      /* print("  ",rr,"  ",exact,"  ",diff_phi), */
>         printf(true, "~&~2t~d~9t~9f~27t~15e ", rr, exact, diff_phi),
>      nstep : 0),
>   nstep : nstep + 1,
>  Sp : Sz,                                /* rotate values for Numerov 
>method */
>   Sz : Sm,
>   phi_p : phi_z,
>   phi_z  : phi_m),
>
> print("  make lists "),
>rrL : makelist(j*h, j, 0, num),                /* return lists of
>length 
>num+1  */
> phiL_list : makelist(phiL[j], j, 0, num),
>remarray(phiL),                                   /* remove array from 
>memory  */
> [rrL, phiL_list])$
>
>fpprintprec : 8$
>========================
>Ted Woollett
>woo...@ch...
>
>
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