48 lines
1.3 KiB
Python
48 lines
1.3 KiB
Python
import scipy.optimize
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import math
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def himmelblau(x, y):
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return (x * x + y - 11) * ( x * x + y - 11) + (x + y * y - 7) * (x + y * y - 7)
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def beale(x, y):
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return math.pow(1.5 - x + x*y, 2) + math.pow(2.25 - x + x*y*y, 2) + math.pow(2.625 - x + x*y*y*y, 2);
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def main():
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if True:
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initial = [-3.670609291875735,3.8585484651848674]
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solution = scipy.optimize.fmin(lambda x: beale(x[0], x[1]),
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initial, retall=True)
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print "loss", beale(solution[0][0], solution[0][1])
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elif False:
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def banana(x, y):
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return (1 - x) * (1 - x) + 100 * (y - x * x) * ( y - x * x)
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initial = [-1.675793744623661,-1.945310341194272]
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solution = scipy.optimize.fmin(lambda x: banana(x[0], x[1]),
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initial, retall=True)
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elif False:
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initial = [4.474377192556858, 0.22207495383918285]
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initial = [-7.185110699385405, 0.01616438291966915]
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solution = scipy.optimize.fmin(lambda x: himmelblau(x[0], x[1]),
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initial, retall=True)
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else:
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solution = scipy.optimize.fmin(lambda x: (x[0]-10) * (x[0]-10), [0], retall=True)
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print solution[0]
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for i, s in enumerate(solution[1]):
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print str(i) + ":", s
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if __name__ == "__main__":
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main()
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