[R] help with simple function

[Berend Hasselman]

On 17-03-2013, at 16:47, Miguel Eduardo Delgado Burbano <mdelgadoburbano at gmail.com> wrote:

> hello all
> 
> I am writing a quite simple script to study dental wear patterns in humans
> and I wrote this function
> 
> sqrt(var(Y1)+var(Y2))^2-4(var(Y1)*(var(Y2)-cov(Y1,Y2)^2)) but appear this
> error message
> 
> Error: attempt to apply non-function
> 

Write 4*( instead of 4( assuming you want to multiply.

> alternatively I wrote this
> sqrt(var(Y1)+var(Y2)^2)-4[(var(Y1)*(var(Y2)-cov(Y1,Y2)^2))]
> 
> but this error message appear
> 
> [1] NA
> Warning message:
> NAs introduced by coercion
> 

[ is an indexing operator. You are trying to index the number 4. Which is impossible.

Berend


> some suggestion to solve this?? thank you so much for your help
> 
> Miguel
> 
> 	[[alternative HTML version deleted]]
> 
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