AttributeError: 'module' object has no attribute 'd2_rho_func'

[polly]

Hi,

this is my first adventure with QuTip, so apologies in advance for the noob Q.

I'm interested in simulating stochastic master equations and so I was trying to generate the example tutorial "Inefficient photon detection: Mixing stochastic and deterministic master equations".  When running the tutorial code (pasting from http://nbviewer.jupyter.org/github/qutip/qutip-notebooks/blob/master/examples/example-smesolve-inefficient-detection.ipynb) I get "AttributeError: 'module' object has no attribute 'd2_rho_func'  " as a message in the Powershell console.

Possibly related to this are the precomputed superopertors 'A'.  I can see that the dissipation terms use elements of A in their definitions.  Once I have run the "from qutip import *" and "from qutip.expect import expect_rho_vec" lines should I be able to see the form of A just by typing "A[0]" for example?  When I do this I get "NameError: name 'A' is not defined".

Following others' instructions I cloned QuTip as g...@github.com:qutip/qutip.git

Thanks for your help and let me know if my question needs more information.

[polly]

so I think I've figured out my problem.  

In the tutorial an option to the smeSolver is set as "map_func=parallel_map".  That option causes the problem.  Once its removed it runs fine.  As a guess it has something to do with whether I'm set up to take advantage of parallel processing (I suppose I'm not), but if anyone can clarify this for me it would be appreciated.  

Thanks.

On Thursday, December 22, 2016 at 9:03:39 PM UTC+11, polly wrote:

Hi,

this is my first adventure with QuTip, so apologies in advance for the noob Q.

I'm interested in simulating stochastic master equations and so I was trying to generate the example tutorial "Inefficient photon detection: Mixing stochastic and deterministic master equations".  When running the tutorial code (pasting from http://nbviewer.jupyter.org/github/qutip/qutip-notebooks/blob/master/examples/example-smesolve-inefficient-detection.ipynb) I get "AttributeError: 'module' object has no attribute 'd2_rho_func'  " as a message in the Powershell console.

Possibly related to this are the precomputed superopertors 'A'.  I can see that the dissipation terms use elements of A in their definitions.  Once I have run the "from qutip import *" and "from qutip.expect import expect_rho_vec" lines should I be able to see the form of A just by typing "A[0]" for example?  When I do this I get "NameError: name 'A' is not defined".

Following others' instructions I cloned QuTip as gitATgithub.com:qutip/qutip.git

[polly]

By following the advice in the post below I was able to run the map_func=parallel_map.  In short, shifting the d1_rho_func and d2_rho_func defns to a separate .py file

Re: ANN: QuTiP 3.1.0.

Well, this is just a guess. Please provide more details about how the failure happen when you try to use map_func=parallel_map. Rob.

1/12/15 by Do Quyen - 15 posts by 8 authors - 656 views