Both objects are numeric, but they differ in structure and I don't know how
to handle both with a single function to get means.
When I try to apply colMeans to a named numeric object like this:
Named num [1:2] 670 314
- attr(*, "names")= chr [1:2] "x" "y"
I get the error messages:
Error in colMeans(centroid) :
'x' must be an array of at least two dimensions
and apply(object,2,mean)
Error in apply(object, 2, mean) : dim(X) must have a positive length
There are something very basic that I'm missing.
2009/8/3 David Winsemius <dwinsem...@comcast.net>
>
> On Aug 3, 2009, at 9:52 AM, Paulo Eduardo Cardoso wrote:
>
> Thanks. Works
> A doubt.
>
> I asked that because I have a loop that can generate objects like that or
> this one
>
>
> str(object)
> Named num [1:2] 670 314
> - attr(*, "names")= chr [1:2] "x" "y"
>
> To avoid using a ifelse() to calculate means of x and y, I'd like a
> function that handle with this named numeric object and that list. Any
> chance of do it with a single function?
>
>
> I do not see any list object. Lists and arrays (of which the two
> dimensional ones are of type "matrix") are quite different basic data
> structures in R. If you interchange the use of those terms you will not get
> useful replies from R users. Those two object both appear to be matrices and
> both should be handled by those functions.
>
>
> 2009/8/3 David Winsemius <dwinsem...@comcast.net>
>
>>
>> On Aug 3, 2009, at 9:07 AM, Paulo Eduardo Cardoso wrote:
>>
>> Maybe a very basic question.
>>> How can I get mean of a object like this
>>>
>>> str(object)
>>>>
>>> num [1:53, 1:2] 734 734 736 734 736 ...
>>> - attr(*, "dimnames")=List of 2
>>> ..$ : NULL
>>> ..$ : chr [1:2] "x" "y"
>>>
>>> I want the mean of both x and y
>>>
>>
>> apply(object, 2, mean)
>>
>> or...
>>
>> colMeans(object) # which will be faster
>>
>>
>> _______________
>>> Paulo E. Cardoso
>>>
>>> [[alternative HTML version deleted]]
>>>
>>> __________________________________________
>>>
>>
>
> David Winsemius, MD
> Heritage Laboratories
> West Hartford, CT
>
>
--
_______________
Paulo E. Cardoso
[[alternative HTML version deleted]]
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