generating functions with maxima



On 8/3/05, Mario  wrote:

> (%i33) f(x,a,b):=listify(setify(exp(flatten(args(transpose(a).x^b)))))$

Agreed, this works. However, it works because exp distributes
over lists, and many other functions (e.g., sin, cos) do not.
Somewhat more generally, then --

  outermap (lambda ([a, b], exp (a * x^b)), coeff, power)  => 
[[%e^-1, %e^-x, %e^-x^2], [1, 1, 1], [%e, %e^x, %e^x^2]]

and then listify (setify (flatten (%))) yields the list you are expecting.

Hmm, a moment's thought suggests 

  map (exp, flatten (args (transpose (a) . x^b)))

which also works. 

Hope this helps,
Robert Dodier