Quantum Equation Addition : Expmv solver

qe_propexpmsolvers.jl

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#####            propexpmsolvers.jl          #####
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abstract QuExponential <: QuPropagatorMethod

immutable QuExpokit <: QuExponential
    options::Dict{Symbol, Any}
end

QuExpokit() = QuExpokit(Dict())

immutable QuExpV <: QuExponential
    options::Dict{Symbol, Any}
end

QuExpmV() = QuExpmV(Dict())

function propagate(prob::QuExpokit, eq::QuantumEquation, t, current_t, current_qustate)
    dt = t - current_t
    next_state = Expokit.expmv(dt, -im*coeffs(operator(eq)), coeffs(vec(current_qustate)), m = get(prob.options, :m, 30), tol = get(prob.options, :tol, 1e-7))
    return QuArray(next_state)
end

function propagate(prob::QuExpmV, eq::QuantumEquation, t, current_t, current_qustate)
    dt = t - current_t
    next_state = ExpmV.expmv(dt, -im*coeffs(operator(eq)), coeffs(vec(current_qustate)), M = get(prob.options, :M, []), prec = get(prob.options, :prec, "double"),
                              shift = get(prob.options, :shift, false), full_term = get(prob.options, :full_term, false))
    return QuArray(next_state)
end