What is the function of the two new options not available in 2D?

In both cases the solver calls the mass matrix function with two inputs (t,y), but the 'weak' option results in implicit solvers using approximations when solving algebraic equations. If the system contains many equations with a strongly state-dependent mass matrix M ( t , y ) , then set MvPattern to a sparse matrix S to specify the sparsity

Explanation:

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