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tutorial:varying_parameters_in_a_simulation [2013/07/29 13:55] juliana |
tutorial:varying_parameters_in_a_simulation [2013/08/14 19:34] admin |
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====== Varying parameters in a simulation ====== | ====== Varying parameters in a simulation ====== | ||

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Nothing should remain constant in a dynamic model. In this respect, Dinamica EGO enables to vary model parameters either in different simulation phases or at each time step. In the Stack tab, a set of Select Functors can be used to change the values of input parameters according to the model step. | Nothing should remain constant in a dynamic model. In this respect, Dinamica EGO enables to vary model parameters either in different simulation phases or at each time step. In the Stack tab, a set of Select Functors can be used to change the values of input parameters according to the model step. | ||

**Using different transition matrices** | **Using different transition matrices** | ||

- | For examples, instead of using only a constant transition matrix, [[:select_transition_matrix|Select Transition Matrix]] enables the use of different transition matrices in a simulation. | + | For examples, instead of using only a constant transition matrix, //[[:Select Transition Matrix]]// enables the use of different transition matrices in a simulation. |

- | To start, load the model “simulate_deforestation_using_multiple_transition_matrix.xml” from \ advanced\multiple_parameters\simulate_deforestation_using_multiple_transition_matrix | + | To start, load the model ''simulate_deforestation_using_multiple_transition_matrix.egoml'' from ''\ advanced\multiple_parameters\simulate_deforestation_using_multiple_transition_matrix'' |

{{ :tutorial:advanced_1.jpg |}} | {{ :tutorial:advanced_1.jpg |}} | ||

- | Using more than one transition matrix in a model is quite simple. In this version of a deforestation model, //Select Transition Matrix// was added to allow the choice of a transition matrix according to the model step. Each transition matrix is entered in a [[:number_transition_matrix|Number Transition Matrix]], click on this functor with the Edit Functor. | + | Using more than one transition matrix in a model is quite simple. In this version of a deforestation model, //[[:Select Transition Matrix]]// was added to allow the choice of a transition matrix according to the model step. Each transition matrix is entered in a //[[:Number Transition Matrix]]//, click on this functor with the Edit Functor. |

{{:tutorial:advanced_2.jpg |}} | {{:tutorial:advanced_2.jpg |}} | ||

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- | **Matrix Number** in this functor indentifies the model step in which this transition matrix begins to operate. The model will use this matrix until it finds a //Number Transition Matrix// with **Matrix Number** that corresponds to the current model step, while from this point onwards //Select Transition Matrix// switches to the new transition matrix. | + | **Matrix Number** in this functor indentifies the model step in which this transition matrix begins to operate. The model will use this matrix until it finds a //[[:Number Transition Matrix]]// with **Matrix Number** that corresponds to the current model step, while from this point onwards //[[:Select Transition Matrix]]// switches to the new transition matrix. |

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<WRAP column 30%> | <WRAP column 30%> | ||

- | <note tip>**TIP**: you can use as many transition matrices as time steps. You just need to add more //Number Transition Matrix// functors and number them according to the model time intervals.</note> | + | <note tip>**TIP**: you can use as many transition matrices as time steps. You just need to add more //[[:Number Transition Matrix]]// functors and number them according to the model time intervals.</note> |

</WRAP> | </WRAP> | ||

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The same procedure applies to the selection of other model parameters, such as the Weight of Evidence | The same procedure applies to the selection of other model parameters, such as the Weight of Evidence | ||

coefficients. | coefficients. | ||

- | Load the model: “simulate_deforestation_using_multiple_transition_matrix_and_weights.xml” from \Examples\advanced\multiple_parameters\simulate_deforestation_using_multiple_transition_matrix_and_weights | + | Load the model: ''simulate_deforestation_using_multiple_transition_matrix_and_weights.egoml'' from ''\Examples\advanced\multiple_parameters\simulate_deforestation_using_multiple_transition_matrix_and_weights'' |

- | A //Select Weights// functor is added to the model to enable the selection of more than one Weights of Evidence coefficient files. A //Number Weight// is inserted within the container //Select Weights// for each Weights of Evidence coefficient file. Another //Load Weights// is added to the model in the outside part of the main loop (//Repeat//). This functor loads the coefficients from a file and is connected to one of the// Number Weights// inside the //Select Weights//. Open each one of the// Number Weights// and edit the **Weight Number** field to define the step when each coefficient file begins to take part in the model. | + | A //[[:Select Weights]]// functor is added to the model to enable the selection of more than one Weights of Evidence coefficient files. A //[[:Number Weight]]// is inserted within the container //[[:Select Weights]]// for each Weights of Evidence coefficient file. Another //[[:Load Weights]]// is added to the model in the outside part of the main loop (//[[:Repeat]]//). This functor loads the coefficients from a file and is connected to one of the //[[:Number Weights]]// inside the //[[:Select Weights]]//. Open each one of the //[[:Number Weights]]// and edit the **Weight Number** field to define the step when each coefficient file begins to take part in the model. |

{{:tutorial:advanced_18.jpg |}} | {{:tutorial:advanced_18.jpg |}} | ||

[[tutorial:using_subregions_in_a_simulation_model|Next Lesson]] | [[tutorial:using_subregions_in_a_simulation_model|Next Lesson]] |