Solve: Error in PROGN [or a callee]: Bind stack overflow.


On Tue, 23 Nov 2010, Julian Andres Klode wrote:

< When trying to run the code below, I get 
< 	Error in PROGN [or a callee]: Bind stack overflow.
< 
< The function preg() is doing regression, returning a term approximating
< the points P. The term is based on 'term', with the variables in 'vars'
< being replaced. When running on a term a^x, solve() results in a bind
< stack overflow; for a * x it works perfectly.
< 
< Hope you can help, as I need this function to work.
< 
< -- Maxima version information:
< Maxima version: 5.22.1
< Maxima build date: 1:16 11/6/2010
< Host type: x86_64-unknown-linux-gnu
< Lisp implementation type: GNU Common Lisp (GCL)
< Lisp implementation version: GCL 2.6.7
< 
< -- Code:
< preg(P, term, vars) := block([eqns, g, res, ratprint: false],
<     g : sum((P[i][2] - subst(P[i][1], x, term))^2, i, 1, length(P)),
<     eqns : makelist(diff(g,vars[i]), i, 1, length(vars)),
<     subst(solve(eqns, vars)[1], term)
< )$
< 
< P : [[1650, 0.545], [1750, 0.728], [1800, 0.906],
<      [1850, 1.171], [1900, 1.608], [1950, 2.517]]$
< 
< preg(P, a ^ x * b, [a, b]);
 
 Is there a reason you are trying to find an exact solution, when
 your input data are floats? The lbfgs package provides an iterative
 floating-point solver. The lsquares package also provides an interface
 that you can use without needing to write lots of code. Both are
 documented in the manual.
 Leo

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