The exact blend is controlled by solution gradients, and nonlinear stability criteria such as TVD or TVB conditions. Finally, to convert from scalar conservation laws to vector conservation laws, most methods use an approach based on waves, either Riemann solvers, sometimes called flux difference splitting, or flux vector splitting. The original research papers use different derivations, notations, and test problems, which obscures the connections between methods. Computational Gasdynamics uses common derivations, notations, and test problems, with extensive cross-referencing, to clearly expose the similarities and differences between methods. Besides modularity, the technical treatment in Computational Gasdynamics distinguishes itself in other ways.
Many textbooks stress linear and locally-linear methods.
Yet CFD is moving progressively towards inherently nonlinear methods. The stress on linearity found in most basic CFD treatments has lead to confusion in the CFD community, even among experts. Unfortunately, many conclusions drawn for linear methods simply do not apply to inherently nonlinear methods. Linearity greatly simplifies things, but at the cost of making the dissimilar seem similar. Computational Gasdynamics is constructed from the ground up to treat nonlinear methods.