|Bill Allombert on Wed, 01 Jul 2009 23:46:34 +0200|
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|Re: How do I ...|
On Wed, Jul 01, 2009 at 04:34:24PM -0400, Bill Daly wrote: > I can't seem to find a function that does this in PARI, but I suspect > there is one, that I've forgotten about. > > I have a vector of Polmods, and another Polmod which I know to be a > rational linear function of the components of the vector. How can I get > PARI to calculate this for me? I suppose you can use plain old linear algebra: reduce the problem to solve AX=B where A is the matrix of the Polmod and B is the vector of the resulting POLMOD. If your POLMOD are in the same number field K, you can use nfalgtobasis to express them in the integral basis, which make it a bit easier to write the matrix. (I do not think PARI has a dedicated function for this task nor for the other, but it can be done by linear algebra). Cheers, Bill.