[Scilab-users] bvode example broken?

[Claus Futtrup]

I confirm the last example in 
https://help.scilab.org/docs/6.1.0/en_US/bvode.html returns the 
following error - on a Windows 10 machine:

--> exec('D:\Userdata\Claus\Documents\Scilab\bvode_example.sce', -1)
  VERSION *COLNEW* OF COLSYS .
  THE MAXIMUM NUMBER OF SUBINTERVALS IS MIN ( 117 (ALLOWED FROM FSPACE), 
124 (ALLOWED FROM ISPACE) )
  THE NEW MESH (OF    4 SUBINTERVALS),     0.000000    0.500000 
1.000000    1.450000    1.900000
  CONVERGENCE AFTER  3 ITERATIONS
  THE NEW MESH (OF    8 SUBINTERVALS),     0.000000    0.250000 
0.500000    0.750000    1.000000    1.225000    1.450000 1.675000    
1.900000
  CONVERGENCE AFTER  1 ITERATIONS
  VERSION *COLNEW* OF COLSYS .
  THE MAXIMUM NUMBER OF SUBINTERVALS IS MIN ( 117 (ALLOWED FROM FSPACE), 
124 (ALLOWED FROM ISPACE) )
  THE FORMER MESH (OF    4 SUBINTERVALS),    0.000000 0.000000    
0.000000    0.000000    0.000000
  THE NEW MESH (OF    2 SUBINTERVALS),     0.000000    0.000000 1.900000
  ****** DOMAIN ERROR IN APPROX ****** X =    0.2141331642D+00 ALEFT 
=    0.0000000000D+00   ARIGHT =    0.0000000000D+00
  ****** DOMAIN ERROR IN APPROX ****** X =    0.9500000000D+00 ALEFT 
=    0.0000000000D+00   ARIGHT =    0.0000000000D+00
  ****** DOMAIN ERROR IN APPROX ****** X =    0.1685866836D+01 ALEFT 
=    0.0000000000D+00   ARIGHT =    0.0000000000D+00
  THE GLOBAL BVP-MATRIX IS SINGULAR
at line   122 of executed file 
D:\Userdata\Claus\Documents\Scilab\bvode_example.sce

bvode: The collocation matrix is singular.



... Line 122 is of course the execution of bvode:

sol=bvodex|(res,ncomp,m,aleft,aright,zeta,ipar,ltol,tol,fixpnt,...
fsub,dfsub,gsub,dgsub,guess);

/Claus

On 15-07-2020 19:39, Rene Djack wrote:
> Hello,
> I' m new to this list and to scilab too!
> Working on bvode, I try the example "Quantum Neumann equation" found 
> in the scilab help and i get the error message
> "Collocation matrix is singular"
> Is this example broken?
> Somebody have the same message?
>
> I'm using scilab 6.10 from scilab-6.10.bin.linux-x86-64.tar.gz on 
> Ubuntu 20.4
>
> Tanks for reading
> Regards
>
>
> _______________________________________________
> users mailing list
> users at lists.scilab.org
> http://lists.scilab.org/mailman/listinfo/users


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.scilab.org/pipermail/users/attachments/20200715/45c1605b/attachment.htm>