Thanks for your suggestion. That also works for indices of class varidx. Gilson. 2007/10/27, Richard B. Kreckel <kreckel@ginac.de>:

Gilson Dallabona wrote:

...

I'm a new user of Ginac and I have found a problem. I need to define an indexed object with six indices or more. However, for an indexed object with more than four indices the compilation returns an error. A simple example is:

symbol Delta("Delta"); varidx mu(symbol("mu"),4), nu(symbol("nu"),4), alpha(symbol("alpha"),4), beta(symbol("beta"),4), sigma(symbol("sigma"),4), lambda(symbol("lambda"),4);

ex e = indexed(Delta,mu,nu,alpha,beta,alpha,beta); cout << e << endl;

returns a compilation error like this

"error: no matching function for call to 'GiNaC::indexed::indexed(GiNaC::symbol&, GiNaC::varidx&, GiNaC::varidx&, GiNaC::varidx&, GiNaC::varidx&, GiNaC::varidx&, GiNaC::varidx&)"

Is there a way to define an indexed object with more than four indices in Ginac?

Just use this indexed constructor signature: indexed::indexed(const ex & b, const exvector & iv). It constructs an indexed object with a specified vector of indices. The indices must be of class idx.

-richy. -- Richard B. Kreckel <http://www.ginac.de/~kreckel/> _______________________________________________ GiNaC-list mailing list GiNaC-list@ginac.de https://www.cebix.net/mailman/listinfo/ginac-list