# Method of entering the metropolis algorithm

Hello everyone I need help I have parameters that have no initial values ​​but they are distributed according to beta and gamma laws a prior and a posterior
1I would like to know when I have to enter the codes on the Markov chains and the draws according to the metropolis algorithm
It is so what I have to enter the codes before or after the distribution of the parameters posterior
2-If possible I would like to have a very small set on the method of grasp to follow for my programming

I am not sure I understand your question. In your mod-file, you have to provide the prior distribution and Dynare will return a posterior distribution. Simple examples are the `fs2000.mod` in the Dynare examples folder and https://github.com/JohannesPfeifer/DSGE_mod/blob/master/RBC_baseline/RBC_baseline_first_diff_bayesian.mod

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Best

please I have another problem I have to program the price of Calvo. but in the equation there is the function sum (from 0 to Infinity) that I don’t know enter on dynare.

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Thank you teacher I will follow the article you send me to rewrite my equations before programming.
Best

excuse me professor when I launches my program on dynare here is what appears
<< ERROR: in the ‘steady_state_model’ Block, variable ‘Y’ is undefined in the declaration of variable ‘y’>>

1. I would like to know what problematic because it no equation in my model which explains Y in my steady-state.

I would also like to know how to run my model with my database on excel.

As always, without the files it is impossible to tell.

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here is the file
programme.mod (4.1 KB)

What are the lines

``````y=(1-alpha)*log(c)+alpha*log(EX)+alpha*v*s+g;
omg_s_c=0.55*y;
``````

in the `steady_state_model`-block supposed to do? In the first line, `Y` is not defined yet and your model does not feature a `y`, only a `Y`.

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OK Master.
Please I would also like to know how to run my model with my database on excel.