[Rd] sd function (PR#11586)

[rfolgueira at yahoo.com]

Full_Name: Ramón Folgueira Roque
Version: 2.7.0
OS: Windows
Submission from: (NULL) (200.11.210.98)


The sd function doesn`t give the same results than older version, when it´s
applied to a data frame object and the object contains some character data.

Ex:
datos=data.frame( )
fix(datos)
          Grupo Vel 
          A     10.1       
          A     9.8            
          B     10             
          B     10             
          A     9.9           
          A     10.1          
          B     NA           
          A     10            

sd(datos,na.rm=T)