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===

**Factorize** an assembled matrix or **manufacture a pre-conditioning matrix**.

The matrix produced by this operator is provided to operator RESOUDRE [U4.55.02] to solve linear systems.

This operator allows:


1. Or to factorize the assembled matrix (into a product of two triangular matrices) for direct methods,


2. Or to build a pre-conditioning matrix for iterative methods in order to accelerate convergence during resolution.

This command is a mandatory prerequisite before calling the RESOUDRE resolution command.

Produces (or enriches) a matr_asse data structure.