Why is `poly` complaining about degree less than number of unique points?

Question

I am trying to generate orthogonal polynomials in R, but I keep getting an error I don't understand ``` > poly(1:1000, 50) Error in poly(1:1000, 50) : 'degree' must be less than number of unique points ``` Surely the number of unique points is 1000? What does it mean? Is this a bug, and if so does anyone know I work around? Edit: This appears to kick in for degree > 27 for any number of points - is this an undocumented limit?

Accepted Answer

Numerical overflow. If you look at the code for `poly`, you'll see it's generating the individual polynomial terms as an intermediate step:

```
X <- outer(x, seq_len(n) - 1, "^")
```

and when `n` (the degree of the polynomial you want) is 50, the resulting terms go up to 1e132.

Why is `poly` complaining about degree less than number of unique points?

Solution

Problem