[R] triangular matrix

[Uwe Ligges]

Cesar Augusto de Freitas Anselmo wrote:
> 
> How I make the below matrix
> 
> | a^0   0       0       ...     0   |
> | a^1   a^0     0       ...     0   |
> | a^2   a^1     a^0     ...     0   |
> |       .                           |
> |       .                           |
> |       .                           |
> | a^n   a^(n-1) a^(n-2) ...     a^0 |
> 
> with no loops, where "a" is a constant?

What about
  ma <- matrix(rep(c(a^(0:n), 0), n+1), nrow=n+1, ncol=n+1)
  ma[upper.tri(ma)] <- 0


Uwe Ligges
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