[R] Error Awareness

Fri Dec 24 18:07:15 CET 2021

Stephen,

I actually happen to like debates and abstractions especially covering multiple languages and domains but not HERE. As you note, some people created this forum for several purposes but the word HELP should provide a clue as to the main purpose. It is not meant to teach R or do homework for people but is somewhere in between and elsewhere. Ideally, it helps people who are a bit stuck somewhere but can already program and need a fresh pair of eyes or some domain knowledge to get over that problem and continue. The Posting Guide spells it out.

There is some latitude but stretching it too far can be a problem. Plenty of people do and I suppose some of my longer messages also make me guilty. And people who repeatedly ask for one thing after another, often are those who should do some independent study before working on the problems as the people who volunteer here generally do not want a full-time unpaid tutoring job.

If you can find another forum that welcomes lively debates on what is good or bad about a language like R or discusses alternative ways to do things or bet practices and so on, or what new features might be helpful, let me know and I might join.

For now, I think I will step aside and focus my efforts elsewhere.

-----Original Message-----
From: Stephen H. Dawson, DSL <service using shdawson.com> 
Sent: Friday, December 24, 2021 9:49 AM
To: Avi Gross <avigross using verizon.net>; 'r-help mailing list' <r-help using r-project.org>
Subject: Re: [R] Error Awareness

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.
>