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Unable to find out steady state

PostPosted: Mon May 01, 2017 7:52 pm
by mhsjnu
Residuals of the static equations:

Equation number 1 : -10.4446
Equation number 2 : 3.8
Equation number 3 : 1.6955
Equation number 4 : Inf
Equation number 5 : 0.86647
Equation number 6 : -0.31565
Equation number 7 : 0
Equation number 8 : Inf
Equation number 9 : -0.95
Equation number 10 : 2.8183



STEADY: The Jacobian contains Inf or NaN. The problem arises from:

STEADY: Derivative of Equation 4 with respect to Variable y (initial value of y: 5000)
STEADY: Derivative of Equation 8 with respect to Variable y (initial value of y: 5000)

STEADY: The problem most often occurs, because a variable with
STEADY: exponent smaller than 1 has been initialized to 0. Taking the derivative
STEADY: and evaluating it at the steady state then results in a division by 0.

Re: Unable to find out steady state

PostPosted: Tue May 02, 2017 10:38 am
by jpfeifer
You cannot use 5000 as a starting value for log output as you will be using
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exp(5000)=Inf

in the model. Also
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exp(g)=rhog*exp(g(+1)/g)+eg;

does not look like a correct equation. Why is there a division by g on the RHS?

Re: Unable to find out steady state

PostPosted: Wed May 03, 2017 11:32 am
by mhsjnu
Dear Professor Jpfeifer, Thanks for valuable suggestion and guide line. But I am unable to solve after correction. I try to solve for steady state value by using MATLAB under .m file. its looks very difficult. Is there any helpful reference for getting initial value? Please help for solving this model.

Re: Unable to find out steady state

PostPosted: Thu May 04, 2017 11:52 am
by jpfeifer
Your equations are still wrong.

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exp(z)=rhoz*exp(z(-1))+e;

has steady state
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eps(z)=0

implying that
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z=-Inf

Please make sure the exp() is consistently used in a correct way.

An infinite element was encountered

PostPosted: Thu May 18, 2017 5:10 pm
by mhsjnu
Please help, Regarding this issues. Thanks in advanced.
"An infinite element was encountered when trying to solve equation(s) 3
with respect to the variable(s): pi."

Re: Unable to find out steady state

PostPosted: Mon May 22, 2017 6:00 pm
by jpfeifer
Again, make sure the exp()-substitution is consistent. In the first equation,
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rn
is not in exp(). In
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exp(Ln((1+rn(+1))/(1+rn)))
it is. For the start, I would make the model run without this type of substitution and only then add the exp()

The steadystate file did not compute the steady state

PostPosted: Wed Jun 07, 2017 5:12 pm
by mhsjnu
Now I try to find out Steady state value by using "steady_state_model" command for the instant of the initial value. Plz help and thanks in Advanced.

Re: Unable to find out steady state

PostPosted: Thu Jun 08, 2017 6:35 am
by jpfeifer
I can only repeat myself. You did not head any of my previous advice. Note that a
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steady_state_model

block requires the full analytical steady state to be computed. It does not seem you did this. For example, z has steady state 0 in the entered AR-process. You have a value for c hard-coded, which also does not seem plausible given that you used an exp()-substitution that implies c is in logs.

Re: Unable to find out steady state

PostPosted: Thu Jun 08, 2017 11:11 am
by mhsjnu
Dear Professor Johannes Pfeifer, I follow your suggestions from the first. But I can not find out the solution. So I try to another way. Now I can understand that it's very difficult. Plz see the attachment, I have corrected by your last suggestions.

Re: Unable to find out steady state

PostPosted: Fri Jun 09, 2017 5:44 am
by jpfeifer
See my very first comment on
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(ln((1+exp(rn))/(1+rn)))=(((1-thetar)*((thetapi*(ln(exp(pi)/pi))+thetay*(ln(exp(y)/y))+thetau*(ln(exp(u))/u))))+thetar*ln((1+exp(rn(-1)))/(1+rn)));

The way you do the exp()-substitution is still not consistent

Re: Unable to find out steady state

PostPosted: Fri Jun 09, 2017 5:29 pm
by mhsjnu
I have done. Is it ok?

Re: Unable to find out steady state

PostPosted: Fri Jun 09, 2017 5:40 pm
by jpfeifer
This is leading nowhere. For the last time, please sit down and check every single equation on whether the exp()-substitution has been done consistently. The last equation for example has an
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n(-1)

not in exp() while it is in exp() everywhere else. As I suggested in the beginning, you should try to solve the model first without any substitution and make sure it runs. That makes debugging much easier.

Re: Unable to find out steady state

PostPosted: Sun Jun 11, 2017 4:09 am
by mhsjnu
I rewrite this equation as follows

(1+exp(rn(+1))/(1+rn))=((1-thetar)*((thetapi*(exp(pi(+1))/pi))+thetay*(exp(y(+1))/y)+thetau*(exp(u(+1))/u)))+thetar*(1+exp(rn(-1))/(1+rn));

Please see the attachment. techT.mod

And Alternative file without substitution: Attachment: techW.mod