[R] Using "cpquery" function from bnlearn package inside loop

[Ryan Morrison]

Thanks Marco,

The cpquery function is definitely easier to use given that my evidence is contained in lists. 

Thanks for your help!

---
Ryan

Ryan Morrison, PE
PhD Candidate
University of New Mexico
Department of Civil Engineering
Centennial Engineering Center, Room 3057
Phone: 505-633-5506
Email: rmorriso at unm.edu
www.ryanmorrison.org


On Oct 10, 2013, at 3:16 AM, Marco Scutari <marco.scutari at gmail.com> wrote:

> Dear Ryan,
> 
> On 9 October 2013 21:26, Ryan Morrison <ryan.r.morrison at me.com> wrote:
>> I'm attempting to use the bnlearn package to calculate conditional probabilities, and
>> I'm running into a problem when the "cpquery" function is used within a loop. I've
>> created an example, shown below, using data included with the package. When
>> using the cpquery function in a loop, a variable created in the loop ("evi" in the
>> example) is not recognized by the function. I receive the error:
>> 
>> Error in parse(text = evi) : object 'evi' not found
> [snip]
> 
> Based on the second example you emailed me off-list, it appears to be
> a scoping problem; that's why the same code works if it's not inside a
> function. I will try to debug this soon, but I am not an expert in R
> parsing mechanisms so it will take some time. In the mean time, you
> can use cpquery(..., method = "lw") instead of the default
> cpquery(..., method = "ls") if your query looks like the one in the
> example. The former does not rely on unevaluated expressions, but
> takes the conditioning values as a list, and it should work
> regardless. However, if you do so I suggest you should install the
> latest bugfix snapshot from bnlearn.com to avoid a few other bugs in
> cpquery(..., method = "lw").
> 
> Cheers,
>    Marco
> 
> -- 
> Marco Scutari, Ph.D.
> Research Associate, Genetics Institute (UGI)
> University College London (UCL), United Kingdom