[boost] [ublas] multiplication of triangular matrices

From: Dimitar Dimitrov (mail_mitko_at_[hidden])
Date: 2007-10-11 03:20:25

       Hello,
 I have to efficiently multiply A'*A, where A is an upper triangular matrix with dimension 150. 
 Defining A as a ublas::triangular_matrix<double, upper> and using the function "prod" is very slow (I used -DNDEBUG flag and noalias).
 If I directly define ublas::matrix<double> A, and use atlas::gemm I get better results. 
 My question is: Is there a way to use the fact that A is triangular in order to speed up the latter computation.
 (I tried using triangular_matrix as an input for atlas::gemm but I got many compilation errors :))
 
 Thank you,
 Dimitar
       
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