[R] Weighted SD

[Peter Dalgaard]

Thomas Lumley wrote:
> On Mon, 1 Feb 2010, David Winsemius wrote:
> 
>>
>> On Feb 1, 2010, at 12:37 PM, Антон Морковин wrote:
>>
>>> Dear all,
>>> what function can be used to calculate weighted SD or/and SE¿
>>>
>>> There's no such stuff in 'base' package.
>>
>> Seems as though lm with a weights argument could be used fairly simply.
>>
> 
> As I have pointed out from time to time, it depends on what the weights 
> are for -- are they precision weights, which lm() can handle, or 
> sampling weights, which it can't?

... or, for completeness, replication weights, which can be handled by 
explicit case replication, but not using the weights= argument.


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