James Sutherland wrote:
On Dec 18, 2008, at 3:46 PM, Eric Niebler wrote:
Daniel Oberhoff wrote:
Now with proto I was wondering how hard it would be to build an et engine for array math. Basically I am interested in general tensor notation, and the resulting expressions should be iteratable efficiently. think (advanced example): a_ij = b_i * (c_j - sum(d_ijk, k = [i-1,1])
I don't understand your notation. What are a_ij et. al.?
Presumably Einstein notation: a_i = vector a_ij = 2D matrix a_ijk = 3D array so that b_i c_j is the outer product of two vectors, producing a matrix...
I guess I'm dense, but I still don't get it. What does this expression mean? a_ij = b_i * (c_j - sum(d_ijk, k = [i-1,1]) At any rate, it requires a domain expert to say how hard it would be to implement a given DSEL, and I'm not a linear algebra domain expert. I've done my best to document Proto extensively, and I can answer questions about Proto but not about linear algebra. -- Eric Niebler BoostPro Computing http://www.boostpro.com