[Help-gsl] RK8pd nan?

[Zine Smith]

I have struggled with receiving a nan inside rk8 that
cause my integration to bomb. It occurs during the
first call to 'evolve'.  Using GDB, I've found the
error to occur during the K4 step on the first element
of the state (dim=6).  Here is the output from GDB for
the elements in the K4 i=0 step.

(gdb) printf  "%g + %g * (%g * %g + %g * %g + %g *
%g)\n",\
y[0],h,b5[0],k1[0],b5[2],k3[0],b5[3],k4[0]
1.37814e+07 + 0.1 * (0.3125 * 1 + -1.17188 * 0.982509
+ 1.17188 * 0.973763)

Given these numbers I would not expect a nan, but when
I display the ytmp[0] element, I get the following in
GDB.

(gdb) printf "%g\n",ytmp[0]
nan

Any help would be greatly appreciated.  I will be more
than happy to provide any code or information that is
needed to help with this issue.

Thanks.
Zine Smith


                
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