68 lines
1.6 KiB
Plaintext
68 lines
1.6 KiB
Plaintext
+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
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Symbolic regression (symbreg): A simple GP example with Open BEAGLE
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Copyright (C) 2001-2003
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by Christian Gagne <cgagne@gmail.com>
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and Marc Parizeau <parizeau@gel.ulaval.ca>
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+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
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Getting started
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===============
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Example is compiled in binary 'symbreg'. Usage options is described by
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executing it with command-line argument '-OBusage'. The detailed help can
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also be obtained with argument '-OBhelp'.
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Objective
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=========
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Find a function of one independent variable and one dependent variable, in
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symbolic form, that fits a given sample of 20 $(x_i,y_i)$ data points,
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where the target function is the quadratic polynomial $x^4 + x^3 + x^2 + x$.
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Terminal set
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============
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X (the independent variable)
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PI
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Ephemeral constants randomly generated in $[-1,1]$
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Function set
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============
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+
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-
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*
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/ (protected division)
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SIN
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COS
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EXP
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LOG (protected logarithm)
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Fitness cases
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=============
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The given sample of 20 data points $(x_i,y_i)$, randomly chosen within
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interval [-1,1].
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Fitness
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=======
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$\frac{1.}{1.+RMSE}$ where RMSE is the Root Mean Square Error on the
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fitness cases.
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Stopping criteria
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=================
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When the evolution reaches the maximum number of generations.
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Reference
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=========
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John R. Koza, "Genetic Programming: On the Programming of Computers by Means
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of Natural Selection", MIT Press, 1992, pages 162-169.
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