32 lines
875 B
Mathematica
32 lines
875 B
Mathematica
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function YESNONA = isconvex(p)
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%ISCONVEX Tries to determine if a scalar expression is convex
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%
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% T = isconvex(p)
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%
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% p: scalar SDPVAR object
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% T: The result (1: convex, 0: concave, NaN: cannot be determined)
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%
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% NOTE : Under development. Do not trust if you have monomials in your model
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%
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% Example
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% sdpvar x y
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% isconvex(x+y) will return 1
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% isconvex(x+y^2) will return 1
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% isconvex(exp(x+y)) will return 1
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% isconvex(-exp(x+y)) will return 0
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% isconvex(max(x,exp(x+y))) will return 1
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% isconvex(-max(x,exp(x+y))) will return 0
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% isconvex(max(x,min(x,-x))) will return NaN
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YESNONA = NaN;
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[F,failure,cause] = expandmodel([],p,sdpsettings('allownonconvex',0,'allowmilp',0));
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if failure == 0
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YESNONA = true;
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else
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[F,failure,cause] = expandmodel([],-p,sdpsettings('allownonconvex',0));
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if failure == 0
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% p is nonconvex
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YESNONA = false;
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end
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end
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