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not able to find steady state

PostPosted: Wed Apr 19, 2017 7:52 pm
by monsoon
Hi,

Attached is a mod file. Every equation has been solved by hand and steady states worked out. But I dont understand for what reason such a simple model is so reluctant to solve. Several errors. Need some help and insight.

Thanks

Re: not able to find steady state

PostPosted: Thu Apr 20, 2017 7:35 am
by jpfeifer
Use
Code: Select all
resid;

before
Code: Select all
steady;

to see that your steady state computations do not match the entered equations. Either your steady state or the entered equations are still wrong.

Re: not able to find steady state

PostPosted: Thu Apr 20, 2017 7:23 pm
by monsoon
When I type resid before steady, it produces two sets of residuals as follows. What is the difference between the two? (One has a large number of errors than the other)

Residuals of the static equations:

Equation number 1 : 0
Equation number 2 : 0
Equation number 3 : 0
Equation number 4 : 0
Equation number 5 : 0
Equation number 6 : 0
Equation number 7 : 0
Equation number 8 : 0
Equation number 9 : 0
Equation number 10 : 0
Equation number 11 : 0
Equation number 12 : 0
Equation number 13 : 0
Equation number 14 : 0
Equation number 15 : 0.044971
Equation number 16 : 0
Equation number 17 : 0
Equation number 18 : 0
Equation number 19 : 0
Equation number 20 : 0
Equation number 21 : 0
Equation number 22 : 0
Equation number 23 : 0
Equation number 24 : 0
Equation number 25 : 0
Equation number 26 : 0
Equation number 27 : 4.6154e-07
Equation number 28 : 0
Equation number 29 : 0
Equation number 30 : 0
Equation number 31 : 0
Equation number 32 : 0
Equation number 33 : 0
Equation number 34 : 0
Equation number 35 : 0
Equation number 36 : 0
Equation number 37 : 0
Equation number 38 : 0
Equation number 39 : 0
Equation number 40 : 0
Equation number 41 : 0
Equation number 42 : 0
Equation number 43 : 0
Equation number 44 : 0
Equation number 45 : 0
Equation number 46 : 0
Equation number 47 : 0
Equation number 48 : 0
Equation number 49 : 0
Equation number 50 : 0
Equation number 51 : 0
Equation number 52 : 0
Equation number 53 : 0
Equation number 54 : 0
Equation number 55 : 0
Equation number 56 : 0
Equation number 57 : 0
Equation number 58 : 0
Equation number 59 : 0
Equation number 60 : 0
Equation number 61 : 0
Equation number 62 : 0
Equation number 63 : 0



SOLVE: maxit has been reached




Residuals of the static equations:

Equation number 1 : 0
Equation number 2 : 0
Equation number 3 : 0
Equation number 4 : 0
Equation number 5 : 0
Equation number 6 : 0
Equation number 7 : 0
Equation number 8 : 0
Equation number 9 : 0
Equation number 10 : 0
Equation number 11 : 0
Equation number 12 : 2.1946e-07
Equation number 13 : 0
Equation number 14 : 0
Equation number 15 : 4.2124e-06
Equation number 16 : -0.00028417
Equation number 17 : 0
Equation number 18 : 0
Equation number 19 : 0
Equation number 20 : 0
Equation number 21 : 0
Equation number 22 : 0
Equation number 23 : 0
Equation number 24 : 0
Equation number 25 : 0
Equation number 26 : 0
Equation number 27 : 4.6154e-07
Equation number 28 : 0
Equation number 29 : 0
Equation number 30 : 0
Equation number 31 : 0
Equation number 32 : 1.4714e-05
Equation number 33 : 6.0038e-05
Equation number 34 : 2.9292e-05
Equation number 35 : -3.7891e-06
Equation number 36 : 2.9568e-06
Equation number 37 : 9.0014e-05
Equation number 38 : -5.0522e-06
Equation number 39 : 0
Equation number 40 : 0
Equation number 41 : 0
Equation number 42 : 0
Equation number 43 : 0
Equation number 44 : 0
Equation number 45 : 0
Equation number 46 : 0.00029758
Equation number 47 : 0
Equation number 48 : 0
Equation number 49 : 0
Equation number 50 : 0
Equation number 51 : 0
Equation number 52 : 0
Equation number 53 : 0
Equation number 54 : 0
Equation number 55 : 0
Equation number 56 : 0
Equation number 57 : 0
Equation number 58 : 0
Equation number 59 : 0
Equation number 60 : 0
Equation number 61 : 0
Equation number 62 : 0
Equation number 63 : 0

Re: not able to find steady state

PostPosted: Thu Apr 20, 2017 9:42 pm
by monsoon
I revised the initval to match equations. Now. there are no residuals but the model does not solve. model_diagnostics also does not indicate anything. What should I do? file is attached. Appreciate any help.

Re: not able to find steady state

PostPosted: Fri Apr 21, 2017 7:46 am
by jpfeifer
The first resid before steady gives the residuals based on the starting values, the one after steady the ones based on the failed steady state finding.

Code: Select all
model_diagnostics

provides information on collinearity, but you don't get there, because you have a steady command before it that throws out an error, so the command is never reached.

Re: not able to find steady state

PostPosted: Sat Apr 22, 2017 9:07 am
by monsoon
when i commented out check, model diagnostics started working.

Re: not able to find steady state

PostPosted: Mon Apr 24, 2017 6:26 am
by jpfeifer
Yes. As I said, you never reached model_diagnostics because of earlier errors.