[R] Error Awareness

Fri Dec 24 15:49:28 CET 2021

Thank you, Avi. I appreciate your reply. I agree maturing code is the 
best move to answer this interrogatory. I express deep thanks for 
contextualizing your response.

I also agree with you responses are becoming a pattern here. A post of 
an open-ended question regarding either a conceptual or stylistic topic 
is answered pervasively with linear thinking. This combination is a 
mismatch of context.

https://www.r-project.org/posting-guide.html

I summarize reading in the R Posting Guide, which is written in English, 
the recommendation to state a specific question involving specific R 
functionality. I read nothing in the R Posting Guide where open-ended 
questions are disallowed or even discouraged. Furthermore, I cannot 
imagine not posting either conceptual or stylistic questions to any 
practice group. If learning is not accomplished by open-ended questions, 
then there is nothing left other than closed-ended (direct) questions.

All the same, the benefit of gaining either tacit understanding or 
wisdom to use the R language by way of open-ended questioning is not 
found in the R Posting Guide as it is either written or practiced. This 
reality impairs the ability to learn about a dialogue member's thought 
process. It also impairs the ability to ever be able to one day offer 
either contract or employment work to anyone demonstrating both intimate 
knowledge of the R language and having the wisdom to implement it 
effectively.

It is inappropriate to recommend modifications to the R Posting Guide in 
this discussion, as it would be out of scope. So, I will not do it.

I close this dialogue as resolved. It is best to post any further 
discussion of this interrogatory in a new dialogue to avoid violating 
the R Posting Guide requirement of the stated Latin term ad hominem.

  https://www.dictionary.com/browse/ad-hominem

  https://en.wikipedia.org/wiki/Ad_hominem#Terminology

  Kindest Regards,
*Stephen Dawson, DSL*
/Executive Strategy Consultant/
Business & Technology
+1 (865) 804-3454
http://www.shdawson.com <http://www.shdawson.com>

On 12/23/21 10:28 PM, Avi Gross via R-help wrote:
> Stephen,
>
> It is becoming a pattern here.
>
> You have been told R allows ways to check for errors as the code is
> interpreted and this DOES NOT distinguish between development aspects and in
> the field. It does not matter if a problem is external like a required file
> not being in place or having a new name or whatever.
>
> Anything that may go wrong can be handled in quite a few ways. Some are
> fairly obvious, such as checking if an expected  list or vector or whatever
> is returned that is empty or not set or is the wrong data type or contains
> some NA or negative numbers and on and on. All kinds of IF statements and
> checks are a way to deal with these and you decide whether to make some kind
> of fix or abort.
>
> But obviously if the error happens outside your code (and sometimes also
> within) you can use various ways R provides to intercept the error and do
> something. Heck, people often use this in advance as a programming tactic
> such as using try() or tryCatch() to something like try to open file1 in the
> current directory and if that fails, in a specified directory and maybe if
> that fails, get it from file2 or maybe standard input ...
>
> Well-written code that wants to be bullet-proof will often be a bit bloated
> as it regularly stops and checks not only for all kinds of error conditions
> but also checks if the variables being used are in the proper format and
> range before being passed to functions that might break, is say you told it
> to use a correlation above 1. It also decides to intelligently deal with the
> errors, when possible.
>
> I have written code that called a statistical analysis (lavaan)  function
> hundreds of thousands of times on randomly generated data and it worked
> fine, except occasionally it broke. As I tended to run it overnight, it was
> a pain to wake up and find it had crashed. No, I am not aware why it
> crashed, but it could have been something as simple as a matrix that could
> not be inverted. But for my purposes, it did not matter as what I would be
> happy to get is knowing it failed, marking associated rows of a data.frame
> accordingly, and filtering out the results in later analyses. So, I wrapped
> not only this call but some others as described above and intercepted the
> rare problem and dealt with it and let my program continue overnight.
>
> Clearly if you expect anomalies to be rare, this is extra overhead. But if
> things do happen, then your code is not robust enough.
>
> -----Original Message-----
> From: R-help <r-help-bounces using r-project.org> On Behalf Of Stephen H. Dawson,
> DSL via R-help
> Sent: Thursday, December 23, 2021 11:17 AM
> To: Bert Gunter <bgunter.4567 using gmail.com>
> Cc: R-help <r-help using r-project.org>
> Subject: Re: [R] Error Awareness
>
> Hi Bert,
>
>
> Thanks for the reply.
>
> The use case I presented involves working code, not diagnosing a script in
> development.
>
> The concern is running a script where something changes outside of the
> script, as I stated. An example of a change is a data source changing
> perhaps the columns in the data source, or even changing the spelling of a
> column. The point is something changes.
>
> The question then becomes how to be aware of the change when the reset of
> the script runs fine, as I presented.
>
> Think of having a script running daily where you are not running it
> manually. How do you know there are errors in the script processing at this
> point?
>
> Does this question now make more sense?
>
>
> *Stephen Dawson, DSL*
> /Executive Strategy Consultant/
> Business & Technology
> +1 (865) 804-3454
> http://www.shdawson.com <http://www.shdawson.com>
>
>
> On 12/23/21 10:49 AM, Bert Gunter wrote:
>> ?tryCatch
>>
>> This list is not meant for tutorials. A web search on "find errors in
>> R code" brought up what appeared to be many resources to address your
>> question. Please make use of such resources before posting here. Also,
>> please read and follow the posting gui)de linked below to find out
>> what sort of help you can expect (and have already received here.
>>
>> Cheers,
>> Bert Gunter
>>
>> "The trouble with having an open mind is that people keep coming along
>> and sticking things into it."
>> -- Opus (aka Berkeley Breathed in his "Bloom County" comic strip )
>>
>> On Thu, Dec 23, 2021 at 3:14 AM Stephen H. Dawson, DSL via R-help
>> <r-help using r-project.org> wrote:
>>> Hi,
>>>
>>>
>>> I am thinking about awareness of errors when an R script runs.
>>>
>>> My concern is I have an error-free script. I run it for months on end
>>> without problems. Then, something changes somewhere causing an error.
>>> My wonderment is how R will tell me I had an error in the script, but
>>> the rest of the script ran without impairment.
>>>
>>> QUESTIONS
>>> What are some of the more helpful options available to an R developer
>>> to capture errors in a script run?
>>>
>>> What are some of the best processes to implement these more helpful
> options?
>>>
>>> Thanks,
>>> --
>>> *Stephen Dawson, DSL*
>>> /Executive Strategy Consultant/
>>> Business & Technology
>>> +1 (865) 804-3454
>>> http://www.shdawson.com <http://www.shdawson.com>
>>>
>>> ______________________________________________
>>> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
>>> https://stat.ethz.ch/mailman/listinfo/r-help
>>> PLEASE do read the posting guide
>>> http://www.R-project.org/posting-guide.html
>>> and provide commented, minimal, self-contained, reproducible code.
> ______________________________________________
> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
> ______________________________________________
> R-help using r-project.org mailing list -- To UNSUBSCRIBE and more, see
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>