Hi Sebastien,On Dec 8, 2009, at 11:37 AM, Sébastien Vauban wrote: Hi Thomas, "Thomas S. Dye" wrote: On Dec 7, 2009, at 11:50 PM, Sébastien Vauban wrote:
[2] I guess one could potentially think about dealing with missing values
more explicitly in org-babel. E.g. there could be a header arg
specifying what values are to be treatyed as missing. Nothing like
that exists currently.
I guess such a feature would be required on the long term. Of course, even
specifying what would be the needed behavior is already difficult, I think.
One must have good knowledge of the multiple languages and environments,
and try to abstract the best behavior out of these.
Side note -- I know, for example, that there is an option in Access to let
it consider the empty string ('') as the NULL value, or not. Clear.
But what's a "NA" value in general? Is 0 always a meaningful value as
numeric? Context-sensitive..
NA is a logical constant of length 1 which contains a missing value
indicator. Whether or not 0 is a meaningful value as numeric depends on your
data and the questions you are asking of it. You don't ask this question,
? I thought I addressed that when asking (to myself) "Is 0 always a meaningful value as numeric?" and answering [that it certainly is] "context-sensitive.." but if I read this thread correctly and you are trying to workaround a data
input problem with R in Org-babel,
No, you misread, or I mis-wrote ;-) I wasn't speaking of R only, saying that "such a feature would be required on the long term [... for] the multiple languages". Thinking at shell-script (with empty strings), SQL code (with empty strings and NULL values), etc. then replacing missing values with 0 in a numeric context to get around the
Org-babel problem is NOT a good idea.
Implementing a fixed interpretation is NOT a good idea. I share your point of view. My comments were: - I think we must be able to write a rule for interpreting "empty" (whatever it means) values; - We should think at what's needed to cover the current and future needs, not focusing on one specific language (R), but thinking at all of them (shell commands, SQL, etc.). Best regards, Seb -- Sébastien Vauban
I agree with you on the importance of having some way to represent missing values in Org-babel that can be translated cleanly and transparently to the representations used by specific languages.
I was responding to one part of your longer message in the context of the message subject, "R questions." I see now that you were asking a more general question. Mea culpa.
All the best, Tom
Thomas S. Dye, Ph.D. T. S. Dye & Colleagues, Archaeologists, Inc. Phone: (808) 529-0866 Fax: (808) 529-0884
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