Non-Linear Optimization - Query
On 18-03-2009, at 18:36, Ravi Varadhan wrote:
system.time(ans.nl <- nleqslv(x=p0, fn=broydt))[1]
user.self
8.17
On my Imac 2.16Ghz and R 2.8.1 and Mac OS X 10.5.6 this took approximately 5 seconds. Interesting is this experiment. I set the jacobian for a starting point with all x-values equal to -1 to a diagonal matrix with 7 on the diagonal (not a bad approximation). Solving the 1000 equation system now takes 1.4 seconds on my computer with Broyden and double dogleg in 26 iterations (only 1 jacobian is needed in the first iteration). So the overhead of calculating the initial jacobian appears to be a bottleneck. Berend