# What does 'scale(center=F)' do?

#### trinker

##### ggplot2orBust
I always thought if you used scale in R with out centering it was basically $$\frac{x_1}{sd_x}$$ but when I try that (scaling and just dividing each element by sd I get 2 different outcomes, though they are close. The help file for scale isn't that helpful here in making me understand what's going on.

Code:
x <- c(1:10, 1000)
scale(x, center=F)
x/sd(x)
Code:
> scale(x, center=F)
[,1]
[1,] 0.003161669
[2,] 0.006323338
[3,] 0.009485007
[4,] 0.012646676
[5,] 0.015808345
[6,] 0.018970015
[7,] 0.022131684
[8,] 0.025293353
[9,] 0.028455022
[10,] 0.031616691
[11,] 3.161669097
attr(,"scaled:scale")
[1] 316.2886

> x/sd(x)
[1] 0.003334814 0.006669628 0.010004442 0.013339256 0.016674071 0.020008885 0.023343699 0.026678513 0.030013327 0.033348141 3.334814117

#### vinux

##### Dark Knight
As per the information in the help, scale(x,center=F) match with

Code:
 x/sqrt(sum(x^2)/(length(x)-1))

[1] 0.003161669 0.006323338 0.009485007 0.012646676 0.015808345 0.018970015
[7] 0.022131684 0.025293353 0.028455022 0.031616691 3.161669097

#### trinker

##### ggplot2orBust
The possibly centered thing threw me I should have just tried it. Thank you Vinux.