[R] Error in rmultinom(n, size, prob) : too few positive probabilities

[Uwe Ligges]

Ethan Johnsons wrote:
> // R 2.3.1
> 
> Can someone please explain why this error returns?
> 
>> y=numeric(100)
>> x=matrix(runif(16),4,4)
>> for(i in 2:100)
> +    {
> +     y[i]=which(rmultinom(1, size = 1, prob = x[y[i-1], ])==1)
> +    }
> Error in rmultinom(n, size, prob) : too few positive probabilities

y is 0, hence prob=x[y[i-1], ] is empty
You can try it out step by step yourself.

Uwe Ligges




> thx much
> 
> ej
> 
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