Commit 49cb0c32 authored by Liam Healy's avatar Liam Healy
Browse files

Use CL RNG object, and not the foreign pointer in simulated annealing

Jame Wright pointed out that the function trivial-example-step tried
to apply the function #'sample to what turns out to be a foreign
pointer, but it should take a CL object.  This is because we are
making a random number generator, passing the foreign pointer to GSL,
and then it is passing that pointer back to our routines so that we
can use it in the step function.  This has been changed so that there
is a special variable cl-generator which is bound to the CL object in
#'simulated-annealing, and then used in the step function, while the
foreign pointer being returned to us is ignored.
parent e8e3d438
;; Simulated Annealing
;; Liam Healy Sun Feb 11 2007 - 17:23
;; Time-stamp: <2009-12-27 10:05:31EST simulated-annealing.lisp>
;; Time-stamp: <2010-04-10 17:22:03EDT simulated-annealing.lisp>
;;
;; Copyright 2007, 2008, 2009 Liam M. Healy
;; Distributed under the terms of the GNU General Public License
......@@ -144,6 +144,7 @@
simulated annealing routines require several user-specified
functions to define the configuration space and energy function."
(let ((sa-state-counter 0)
(cl-generator)
(user-state-maker-function state-maker-function)
(user-energy-function energy-function)
(user-step-function step-function)
......@@ -151,10 +152,12 @@
(user-copy-function copy-function))
(declare (special
sa-state-counter
cl-generator
user-state-maker-function user-energy-function
user-step-function user-metric-function
user-copy-function))
(make-sa-states 4)
(setf cl-generator generator)
(let ((x0-p (make-new-sa-state state-values)))
(simulated-annealing-int
(list n-tries iterations-fixed-T step-size k t-initial mu-t t-min)
......@@ -194,10 +197,16 @@
(declare (type double-float x) (optimize (speed 3) (safety 1)))
(* (exp (- (expt (1- x) 2))) (sin (* 8 x)))))
(defun trivial-example-step (generator state step-size)
(declare (type double-float step-size) (optimize (speed 3) (safety 1)))
(defun trivial-example-step (rng-mpointer state step-size)
(declare
(type double-float step-size) (optimize (speed 3) (safety 1))
;; Ignore the RNG foreign pointer because it doesn't do us
;; much good, we want the CL object which we'll get from
;; the dynamical environment.
(ignore rng-mpointer)
(special cl-generator))
(symbol-macrolet ((x (maref state 0)))
(let ((rand (sample generator :uniform)))
(let ((rand (sample cl-generator :uniform)))
(declare (type double-float rand))
(setf x (+ (the double-float x) (- (* 2.0d0 rand step-size) step-size))))))
......
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