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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-14 13:40:54 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-14 13:40:54 +0000 |
commit | 317c0644ccf108aa23ef3fd8358bd66c2840bfc0 (patch) | |
tree | c417b3d25c86b775989cb5ac042f37611b626c8a /deps/lua/test/bisect.lua | |
parent | Initial commit. (diff) | |
download | redis-317c0644ccf108aa23ef3fd8358bd66c2840bfc0.tar.xz redis-317c0644ccf108aa23ef3fd8358bd66c2840bfc0.zip |
Adding upstream version 5:7.2.4.upstream/5%7.2.4
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | deps/lua/test/bisect.lua | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/deps/lua/test/bisect.lua b/deps/lua/test/bisect.lua new file mode 100644 index 0000000..f91e69b --- /dev/null +++ b/deps/lua/test/bisect.lua @@ -0,0 +1,27 @@ +-- 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) |