acroy / QuDOS.jl

Quantum Dynamics of Open Systems in Julia
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Allow complex scalar inputs for expmv function #3

Closed i2000s closed 10 years ago

i2000s commented 10 years ago

In the current expmv function setting, the scalar _t_ input is limited to real numbers. In reality, to speed up the computing time, one can combine im/hbar_t as the scalar input _t* to avoid the costly scalar times matrix operation in the matrix _A_. So, one solution is to allow complex type of _t_ inputs as well.

acroy commented 10 years ago

I don't know if this is readily possible with the current expmv which treats t basically as (real) time and uses adaptive step sizes. One could separately treat the case with purely imaginary t, but I am not sure it matters compared to the time used for the propagation itself. Anyways I will have a look.

BTW, it might be better to post issues concerning expmv in the new package Expokit.jl, which will replace the implementation here and maybe provide other approaches.

acroy commented 10 years ago

This should work now.