[SciPy-Dev] Making lobpcg support complex matrix

Pauli Virtanen pav@iki...
Wed Oct 17 17:17:33 CDT 2012

Gregory Crosswhite <g.crosswhite <at> uq.edu.au> writes:
> Anyway, I don't know much about lobpcg so there might be some issue that 
> I've missed in simply adding ".conj()" everywhere a ".T" appeared to fix 
> the dot products.  I do think it would be very nice, though, to be able 
> to use lobpcg for complex matrices, and so I would be willing to submit 
> a patch towards this end.

The original LOBPCG paper IIRC talked only about real symmetric
problems, but it seems other existing implementations accept also
Hermitian input.

So yes, a patch fixing the implementation in Scipy for complex
Hermitian matrices (plus adding tests) would be welcome.

The easiest way (for us, not necessarily for you at least
the first time :) to submit it would be via a pull
request on Github; not a requirement though.

As Nils said, there's a ticket with at least some work done in this


I'm not sure what is the exact status with that, but you may want
to take a look if it is of some help.

Pauli Virtanen

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