Error using solve command of symbolic toolbox

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Victor
Victor 2014-4-5
评论： Victor 2014-4-8
I wrote a code to get a solution for the DSGE model I am working on but the S function was empty at first (when I trying to get the solution using sectors by sector) then later I had this error (when I wrote the whole equation at a go): Error using sym>checkindex (line 2429) Index must be a positive integer or logical.
Error in sym>privformatscalar (line 2376) checkindex(x);
Error in sym>privformat (line 2360) s = privformatscalar(x);
Error in sym/subsref (line 1578) [inds{k},refs{k}] = privformat(inds{k});
Please I need a genuine help. Thank you :)

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Walter Roberson
Walter Roberson 2014-4-5
Your expression includes k(-1) and ppb(-1) which are attempts to access arrays at index negative one.
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Walter Roberson
Walter Roberson 2014-4-6
编辑：Walter Roberson 2014-4-7
Sometimes there just isn't a closed form solution to a problem.
When you use solve() in the form you are using, each of your numeric constants is being converted from (inherently in-exact) floating point into (exact) rational values, and then an exact solution is sought. If you want to approximate, get a numeric solution, then you need to set it up slightly differently.
Are you aware that one of your left hand sides is s-s (which would of course be 0) ?
You are attempting to solve 49 equations in 62 variables, unless some of those variables (other than coef) are being loaded with the "load" statement. You will almost never find a solution when you have more variables than equations.
Victor
Victor 2014-4-8
Walter, Thank you for the help. I hope you won't give up on me. I missed out on the 50th equation but I included it. I have 62 equations with if I added the equation for the (12) shocks 'epsa' etc. The equations for the shocks are AR(1) so this may not be right ( I tried but got some wrong values). The aim is to get a balanced growth path for the equation when I write them in steady state that is why I didn't add them. Please see the attached file, I made some adjustments and commented out the last 12 equations.

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