Hi all,

Is there a way to convince Eigen to turn something of the form

a.exp() * b.exp() where a,b are Arrays

into (a+b).exp() and similarly for quotients?

Can one design a plugin to recognise these kinds of expression before evaluation?

Thanks,
MT.

In Eigen 3.3 you will be able to do that quite easily. In the meantime you might try to do a partial template specialization of:

CwiseBinaryOp<scalar_product_op<Scalar>, CwiseUnaryOp<scalar_exp_op<Scalar>,Lhs>, CwiseUnaryOp<scalar_exp_op<Scalar>,Rhs>

and make it inherit something of the form:

CwiseUnaryOp<scalar_exp_op<Scalar>, CwiseBinaryOp<scalar_sum_op<Scalar>, Lhs, Rhs> >

with appropriate constructors.