[ADMB Users] bug?

dave fournier davef at otter-rsch.com
Wed Jul 13 15:00:48 PDT 2011

Its not really a bug.  when you declare

        dvar_vector y;

it creates an unallocated vector.
When you assign a vector to an unallocated vector it
does a shallow copy.  But when you assign a number
(which is NOT a vector of size 1) it will depend on how the
assignment operator was written.

         y=K/(1.0+(K/n0-1.0)*exp(-r*t));    // y is still unallocated.

If you had written your function as

  dvar_vector logisticK( const dvector& t,  const prevariable& K,  const 
prevariable& r,  const dvar_vector& n0)
         dvar_vector y=K/(1.0+(K/n0-1.0)*exp(-r*t));  // tries to invoke 
a copy constructor but there isn't one
       return (y);

you would have got an error message.

In this case it does nothing because there is no size information
so an unallocated vector is returned.

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