## Glas :## Re: [glas] norms and inner products for vectors of matrices |

**From:** Karl Meerbergen (*Karl.Meerbergen_at_[hidden]*)

**Date:** 2006-01-17 04:15:08

**Next message:**Toon Knapen: "[glas] mapping expressions to backend"**Previous message:**Jerzy Wasniewski: "[glas] PARA'06, Umea, Sweden, June 18-21, 2006"**In reply to:**Peter Gottschling: "Re: [glas] norms and inner products for vectors of matrices"**Next in thread:**Andrew Lumsdaine: "Re: [glas] norms and inner products for vectors of matrices"**Reply:**Andrew Lumsdaine: "Re: [glas] norms and inner products for vectors of matrices"

Hi,

Here is a question about nested vectors.

Suppose I have

vector< vector< double > > v ;

vector< double > w ;

double d ;

d*v : scalar times vector;

trans(w)*w: dot product of vector of vector with vector of vector: sum_i

trans(w[i])*w[i]

trans(v)*v: dot product of vector with vector: sum_i v[i]*v[i]

How should trans(v)*w be interpreted?

* result is a vector<double> which is the sum: sum_i v[i]*w[i] ?

* result is a vector<double> with element i being: trans(v)*w[i] ?

Best,

Karl

**Next message:**Toon Knapen: "[glas] mapping expressions to backend"**Previous message:**Jerzy Wasniewski: "[glas] PARA'06, Umea, Sweden, June 18-21, 2006"**In reply to:**Peter Gottschling: "Re: [glas] norms and inner products for vectors of matrices"**Next in thread:**Andrew Lumsdaine: "Re: [glas] norms and inner products for vectors of matrices"**Reply:**Andrew Lumsdaine: "Re: [glas] norms and inner products for vectors of matrices"