> The integral in question is a surface integral, and the function in question > is > reasonably well behaved. It is based around spherical harmonics so will > involve sinusoidal type variations with potentially quite rapid oscillations, > but > no singularities etc. I would be grateful for any advice on what the best way > of approaching this is. It looks like it will be the bottleneck in my problem, > so I would like to speed it up as much as possible - at least for a reasonable > amount of effort invested!
I admittedly know next-to-nothing about your problem particulars but feel like FFT-variants might be useful as an approximate quadrature technique. Does anything discussed in this posting http://earthcubed.wordpress.com/2009/08/17/recursive-numeric-integration-the-fft-and-spherical-harmonics/ sound useful? - Rhys
