init_SIELens(x_c::RV=0.0, y_c::RV=0.0, v_d::RV=NaN, x_s::RV=NaN, eps::RV=NaN, pa::RV=NaN)

Initialize singular isothermal ellipsoid (SIE) lens with the given parameters.

potential!(ψ::T, θx::T, θy::T, θxc::RV, θyc::RV, vd::RV, θs::RV, ϵ::RV, pa::RV) where T <: RV

potential!(ψ::T, θx::T, θy::T, θxc::RV, θyc::RV, vd::RV, θs::RV, ϵ::RV, pa::RV) where T <: ROA

deflection!(ψx::T, ψy::T, θx::T, θy::T, θxc::RV, θyc::RV, vd::RV, θs::RV, ϵ::RV, pa::RV) where T <: RV

deflection!(ψx::T, ψy::T, θx::T, θy::T, θxc::RV, θyc::RV, vd::RV, θs::RV, ϵ::RV, pa::RV) where T <: ROA

jacobian!(ψxx::T, ψyy::T, ψxy::T, θx::T, θy::T, θxc::RV, θyc::RV, vd::RV, θs::RV, ϵ::RV, pa::RV) where T <: RV

jacobian!(ψxx::T, ψyy::T, ψxy::T, θx::T, θy::T, θxc::RV, θyc::RV, vd::RV, θs::RV, ϵ::RV, pa::RV) where T <: ROA