minix/external/mit/lua/dist/test/bisect.lua
Lionel Sambuc 11be35a165 Importing NetBSD "Kyua" test framework
To do so, a few dependencies have been imported:

 * external/bsd/lutok
 * external/mit/lua
 * external/public-domain/sqlite
 * external/public-domain/xz

The Kyua framework is the new generation of ATF (Automated Test
Framework), it is composed of:

 * external/bsd/atf
 * external/bsd/kyua-atf-compat
 * external/bsd/kyua-cli
 * external/bsd/kyua-tester
 * tests

Kyua/ATF being written in C++, it depends on libstdc++ which is
provided by GCC. As this is not part of the sources, Kyua is only
compiled when the native GCC utils are installed.

To install Kyua do the following:

 * In a cross-build enviromnent, add the following to the build.sh
   commandline: -V MKBINUTILS=yes -V MKGCCCMDS=yes

WARNING:
  At this point the import is still experimental, and not supported
  on native builds (a.k.a make build).

Change-Id: I26aee23c5bbd2d64adcb7c1beb98fe0d479d7ada
2013-07-23 20:43:41 +02:00

27 lines
645 B
Lua

-- 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)