[R] count appearence of zero in a vector
msuzen at gmail.com
Fri Jan 4 18:26:57 CET 2013
On 4 January 2013 17:47, Bert Gunter <gunter.berton at gene.com> wrote:
> On Fri, Jan 4, 2013 at 7:44 AM, Suzen, Mehmet <msuzen at gmail.com> wrote:
>> I am always reserved about types and not sure how R auto casting works
>> In a large code using many different packages, I think being reserved
>> this would not hurt.
>> Also, are there anyway to force R to be "strongly typed" similar to
>> Occaml etc...
> Yes (I think). Use S4. See. e.g. Chambers: Software for Data Analysis"
> Programming in R
Thank you Bert for point out S4. Here is one trivial example:
> setClass("integerVector", representation(x="integer"))
> iv at x <- c(1, 0, 1, 0, 2, 3)
Error in checkSlotAssignment(object, name, value) :
assignment of an object of class “numeric” is not valid for slot ‘x’
in an object of class “integerVector”; is(value, "integer") is not
> iv at x <- as.integer(c(1, 0, 1, 0, 2, 3))
So this is pretty safe:
> sum(iv at x == 0)
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