Re: suggestions on how to do this

2005-04-27 Thread bwaha
Hi bgs Many thanks. This generates the correct coefficients. I am studying your implementation now. I've not used a dictionary of dictionaries before so there's a bit of a learning curve going on right now. However I can see that b[k] holds the relevant info (coefficients and powers) so I can eas

Re: suggestions on how to do this

2005-04-27 Thread bgs
You could probably use scipy.base.polynomial, but it's easy enough to implement a polynomial yourself. Just use a dict-- each key represents the power and each value the coefficient of the polynomial. You didn't say exactly how efficient you need this. It takes only a couple seconds to sum 100 o

Re: suggestions on how to do this

2005-04-27 Thread cfriedl
Hi Bengt OK, that's right. So I'm curious how you did this. And any comments on how to collect coefficients of like powers in your result. Be Well and Happy Always Chris -- http://mail.python.org/mailman/listinfo/python-list

Re: suggestions on how to do this

2005-04-27 Thread cfriedl
Hi Terry I apprecaite the advice. Briefly I'm familiar with the math (its an eigenvalue problem in fluid flow) but not so much with python (3 months on and off), hence my post here. I'm looking for python advice on how to implement this effectively. I love python and would like to use it well. As

Re: suggestions on how to do this

2005-04-27 Thread Kay Schluehr
Seems You are looking for a generating function of a recurrence relation. There is a standard text about this topic written by Herbert S. Wilf downloadable from his homapage: http://www.cis.upenn.edu/~wilf/ Regards, Kay -- http://mail.python.org/mailman/listinfo/python-list

Re: suggestions on how to do this

2005-04-27 Thread Bengt Richter
On Wed, 27 Apr 2005 11:34:53 GMT, "chris" <[EMAIL PROTECTED]> wrote: >The problem I have is as follows: > >I have a recursive function b(k) > >b(k) = -(A/k**2)*(b(k-2) - b(k-5)) >k<0, b(k)=0 >k=0, b(k)=1 >k=1, b(k)=0 > >eg. b(2) = -A/4 > b(3) = 0 > b(4) = A**2/64 > >note that as k increa

Re: suggestions on how to do this

2005-04-27 Thread Terry Reedy
"chris" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] > I have a recursive function b(k) > > b(k) = -(A/k**2)*(b(k-2) - b(k-5)) This is specifically called a recurrence relation/ [snip] > When this is expanded I get a polynomial F(A). I want to determine the > coefficients of the

suggestions on how to do this

2005-04-27 Thread chris
The problem I have is as follows: I have a recursive function b(k) b(k) = -(A/k**2)*(b(k-2) - b(k-5)) k<0, b(k)=0 k=0, b(k)=1 k=1, b(k)=0 eg. b(2) = -A/4 b(3) = 0 b(4) = A**2/64 note that as k increases b(k) can itself be a sum of terms in powers of A rather than a single power of A