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authorJeremy Allison <jra@samba.org>2008-12-18 15:40:05 -0800
committerJeremy Allison <jra@samba.org>2008-12-18 15:40:05 -0800
commit4283ae489b6e227beba196e8a315a9727f03cc07 (patch)
tree7308561653b9e52eab8fc13181c0ad41ae2da208 /source3/lua-5.1.4/test/bisect.lua
parentf9bb8fbe832409893b17f2113d7b35b9ffe91540 (diff)
parentd031472227b44d040698e6dff52dc79028fde854 (diff)
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Merge branch 'master' of ssh://jra@git.samba.org/data/git/samba
Diffstat (limited to 'source3/lua-5.1.4/test/bisect.lua')
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diff --git a/source3/lua-5.1.4/test/bisect.lua b/source3/lua-5.1.4/test/bisect.lua
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+-- bisection method for solving non-linear equations
+
+delta=1e-6 -- tolerance
+
+function bisect(f,a,b,fa,fb)
+ local c=(a+b)/2
+ io.write(n," c=",c," a=",a," b=",b,"\n")
+ if c==a or c==b or math.abs(a-b)<delta then return c,b-a end
+ n=n+1
+ local fc=f(c)
+ if fa*fc<0 then return bisect(f,a,c,fa,fc) else return bisect(f,c,b,fc,fb) end
+end
+
+-- find root of f in the inverval [a,b]. needs f(a)*f(b)<0
+function solve(f,a,b)
+ n=0
+ local z,e=bisect(f,a,b,f(a),f(b))
+ io.write(string.format("after %d steps, root is %.17g with error %.1e, f=%.1e\n",n,z,e,f(z)))
+end
+
+-- our function
+function f(x)
+ return x*x*x-x-1
+end
+
+-- find zero in [1,2]
+solve(f,1,2)