neil revised this gist 11 months ago. Go to revision
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neil revised this gist 11 months ago. Go to revision
No changes
neil revised this gist 11 months ago. Go to revision
1 file changed, 41 insertions
implicit_relaxation.jl(file created)
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| 1 | + | using McCormick, BenchmarkTools | |
| 2 | + | ||
| 3 | + | """ | |
| 4 | + | Direct relaxation of implicit function | |
| 5 | + | """ | |
| 6 | + | function direct_relax(f, x, p) | |
| 7 | + | delta = Inf | |
| 8 | + | while delta > 1e-8 | |
| 9 | + | x_prev = x | |
| 10 | + | x = f(x, p) | |
| 11 | + | delta = abs(x_prev.cv - x.cv) + abs(x_prev.cc - x.cc) | |
| 12 | + | end | |
| 13 | + | ||
| 14 | + | return x | |
| 15 | + | end | |
| 16 | + | ||
| 17 | + | """ | |
| 18 | + | Faster alternative | |
| 19 | + | """ | |
| 20 | + | function fast_direct_relax(f, x, p) | |
| 21 | + | delta = Inf | |
| 22 | + | while delta > 1e-8 | |
| 23 | + | x_prev = x | |
| 24 | + | x_m = x.cv + .5 * (x.cc - x.cv) | |
| 25 | + | x = f(x_m, p) | |
| 26 | + | delta = abs(x_prev.cv - x.cv) + abs(x_prev.cc - x.cc) | |
| 27 | + | end | |
| 28 | + | ||
| 29 | + | return x | |
| 30 | + | end | |
| 31 | + | ||
| 32 | + | f(x, p) = (p - (p^3)/6 + (p^5)/120)*x^(-1/2) + 100 | |
| 33 | + | ||
| 34 | + | p = MC{1,NS}(1.0, 1.0, Interval(0.5, 5.0)) | |
| 35 | + | x = MC{1,NS}(1.0, 1.0) | |
| 36 | + | ||
| 37 | + | res = @btime direct_relax(f, x, p) | |
| 38 | + | println(res) # 342.860 μs (2414 allocations: 96.52 KiB) MC{1, NS}(99.8362536820914, 100.40188539116205, [97.9454, 103.135], [0.0], [0.0], true) | |
| 39 | + | ||
| 40 | + | res = @btime fast_direct_relax(f, x, p) | |
| 41 | + | println(res) # 2.972 μs (301 allocations: 4.75 KiB) MC{1, NS}(99.8675794497822, 100.37248484959062, [97.9679, 103.101], [0.0], [0.0], true) | |
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