Displaying 2 results from an estimated 2 matches for "_equals_".
2017 Oct 25
0
Problem Subsetting Rows that Have NA's
...ore time studying the language. The help pages are precise but terse, and you need to spend time with the examples and with other tutorial material to recognize the gotcha's.
Here's a couple of possibly helpful rules regarding "[[" and "[" and logical indexing:
Nothing _equals_ NA.
Selection operations with NA logical index item return NA. (Justified as a warning feature as I understand it.)
"[" always returns a list.
"[[" returns only one thing, but even that thing could be a list.
Generally you want "[[" if you plan on testing for equality...
2017 Oct 25
4
Problem Subsetting Rows that Have NA's
On 10/25/2017 4:38 AM, Ista Zahn wrote:
> On Tue, Oct 24, 2017 at 3:05 PM, BooBoo <booboo at gforcecable.com> wrote:
>> This has every appearance of being a bug. If it is not a bug, can someone
>> tell me what I am asking for when I ask for "x[x[,2]==0,]". Thanks.
> You are asking for elements of x where the second column is equal to zero.
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