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functions in strategy_python are descibed here == Initialize == calls ''Initialize'' and ''InitializeElements'' of the ''Scheme'' *''Initilize'' is intended to be called just once when the strategy is initialized *''InitializeElements'' calls [[Initialize]] function of the elements ==[[Solve]]== This function is called at every time step to solve the problem. the order of calls is as follow *Initializations needed and similar for ''all steps'' are done by [[Initialize]]. First of all it checks if [[Initialize]] is called or no so just in the first call of '''Solve''', scheme and elements are initialized and then corresponding flag turns out to True *Initializations needed for ''every step'' is done by [[InitializeSolutionStep]]. *Predict to start nonlinear iteration is done by ''Predict'' function.It calls predict of the corresponding [[scheme]].For example in Bossak scheme it consider Xnew=Xold+Vold*deltaT and then ''Update'' velocity and acceleration with this new displacement. *''ExecuteIteration'' does a nonlinear iteration and return 0.( for the first iteration which is out of iteration loop norm is not calculated == [[InitializeSolutionStep]] == In principle this function calls its counterpart in [[builder_and_solver]] and [[scheme]] but before if it is necessary the new set of DOFs to be solved in this iteration is identified and related changes are done by following functions of [[builder_and_solver]]: [[SetUpDofSet]], [[SetUpSystem]] and [[ResizeAndInitializeVectors]]. what do the [[initializesolutionstep]] of [[builder_and_solver]] and [[scheme]] do? I have no example for builder_and_solver. I'm using residulabased_elimination_builder_and_solver and this function does nothing but for scheme, for example Bossak, it does something. It calls initializesolutionstep of the Scheme that calls this function for [[element]] and [[condition]] and also calculate some constants for Bossak scheme. == ExecuteIteration == following steps are done to execute a nonlinear iteration *''initializeNonlinIteration'' of the ''scheme'' is called. In Bossak scheme it does nothing! *''BuildAndSolve'' of corresponding builder_and_solver is called. As it is clear it builds the system and solve it for the unknowns. build process is done by a function named ''CalculateSystemContributions'', defined in the ''scheme'', which is called by ''Build'' function of the builder_and_solver. In a loop over all elements, ''CalculateSystemContributions'' calls following functions of the element **[[InitializeNonLinearIteration]] **[[CalculateLocalSystem]] **[[MassMatrix]] **[[DampMatrix]] **[[EquationIdvector]] and then add them together with constants defined by the ''scheme''. The same procedure is exactly done for ''condition'' instead of ''element'' by ''Condition_CalculateSystemContributions''. *''Update'': Of course after solving the system update is needed. it is done by the update function of the corresponding scheme. *''Movemesh'': if it is necessary,It is identified by ''movemeshflag'', nodes are moved. ''MoveMesh'' is defined in ''Kratos>python>add_strategies_to_python.cpp'' *''FinalizeNonLinIteration'': calls this function of elements and conditions.this function is called at the end of every iteration. *''ExecuteIteration'' returns the second norm of ''Dx'' or zero.

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