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Ajay Askoolum wrote:Quick question: If you have two variables each being Missing Value, and compared them: would the result be true or a Missing Value?
myVar~#Missing Value#
jbrobston wrote:0 is not adequate
jbrobston wrote:If ignoring them would "keep many other good things from being able to happen" I presume you envision many other good things that could be done if missings were added to the language. What do you see as being those good things? I don't see how adding a feature and being able to ignore it if present detracts anything from the language in its current form.
jbrobston wrote:And how is zilde usable as a substitute for the NA in R? Summing a vector containing a zilde results in zilde, not a sum. The rank of a vector containing a zilde includes the zilde.
Very well - I accept the reprimand as I don't know much about R. (After all, APL is often considered to be a math-only language.) But isn't that how it's marketed? And isn't that what prompted it's creation (though I may be off-base here)? And isn't that what you've all been talking about here? And isn't that what it's mostly used for? I'm thinking about it in a practical way rather than trying to describe its functional limitations.jbrobston wrote:And you might want to read "Programming with Data" before you jump to the conclusion that R was purpose made for statistics.
Davin Church wrote:jbrobston wrote:If ignoring them would "keep many other good things from being able to happen" I presume you envision many other good things that could be done if missings were added to the language. What do you see as being those good things? I don't see how adding a feature and being able to ignore it if present detracts anything from the language in its current form.
There is a concept that says that "any error behavior can be replaced with functionality without changing the base language", so in that respect adding a missing value can't hurt. But if you're going to support missings you don't want to support one thing well without doing a good job supporting everything. For instance, what would happen if the designers of APL decided that dyadic ⍴ was useful for reshaping character arrays but didn't make it also work just as well on numeric values? Where would we be now?
I think that adding a missing value is fine, in general. I'm just trying to suggest that we think through every possible design situation and make it as flexible and useful as possible. For instance, if we created a missing value I wouldn't want it to JUST be ignored during summing. Maybe I might also want it to be ignored if I catenated it into a series of character vectors. Or if it gets ignored when taking the ⍴ of a vector, what happens if you take the ⍴ of a matrix containing scattered missings? Or what happens if you use ⍴ to reshape a vector or matrix containing missings. You don't want to add a language feature that leaves functional "holes" when you try to extend its behavior.
Davin Church wrote:jbrobston wrote:And how is zilde usable as a substitute for the NA in R? Summing a vector containing a zilde results in zilde, not a sum. The rank of a vector containing a zilde includes the zilde.
I'm not suggesting a direct replacement for it, but a way to simulate the need for it in specific circumstances. For instance, summing a vector with ⍬ could be done by simply removing them with ~⊂⍬ first.
Davin Church wrote:Very well - I accept the reprimand as I don't know much about R. (After all, APL is often considered to be a math-only language.) But isn't that how it's marketed? And isn't that what prompted it's creation (though I may be off-base here)? And isn't that what you've all been talking about here? And isn't that what it's mostly used for? I'm thinking about it in a practical way rather than trying to describe its functional limitations.jbrobston wrote:And you might want to read "Programming with Data" before you jump to the conclusion that R was purpose made for statistics.
Davin Church wrote:Ajay Askoolum wrote:Quick question: If you have two variables each being Missing Value, and compared them: would the result be true or a Missing Value?
In some languages that I've encountered before, a missing value IS equal to another missing value and NOT equal any regular value. Of course, if you go by Excel's way of doing things, any comparison with #NA is also #NA.
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