CosmoSim Simulation Model

Simulator Library¶

At the highest level, the simulator consists of three components.

1. lens model (Lens) which implements a mathematical description of the lens.

2. source model (Source) which gives the mathematical description of the source and produce undistorted images of it.

3. simulation model (SimulatorModel) which calculates distorted images by using the lens and source models. Some simulation models are couples the lens model for various reasons. Two generic simulation models are supported.

   • Raytrace Simulation

   • Roulette Model

Modelling the Lens¶

The software aims to separate the simulation model (LensModel) and the actual lens (Lens), as is seen in the class diagram above. This is only partly implemented so far. The two simulation models for point mass lenses integrate the lens in simulation model. Decoupling them appears to be non-trivial.

Only one actual lens model has been fully implemented, namely SIS. The SIE model works in the Raytrace model but not yet in the Roulette model. These models can be used either directly, or in a sampled version by wrapping it inside SampledModel. The sampled model is really intended for lenses where an algebraic expression for the lens potential $\psi$ is not known, but the only case implemented is sampling an computable function.

Auxiliaries¶

The simaux.cpp file provides the following:

• factorial_()

• refLines() to draw the axis cross