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# NMaximize gives wrong result

Posted 9 years ago
 Hi, i am experiencing this issue with NMaximize function. The function returns a maximum value 0.999985, but in graph shows that the maximum is 0.999706. Does anyone knows why is this happening?
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Posted 9 years ago
 Hi again, i solved my problem including Method -> "NelderMead" to my NMaximize function and the result is rigth now.
Posted 9 years ago
 Sorry, I was unclear. Run Availability on the actual value returned by NMaximize. Mathematica clips numbers when displaying them. This is so that the output stays readable. For example: N[Pi] 3.14159 InputForm@% 3.141592653589793 InputForm shows you the actual output of a command. Try using it to see what the rest of the decimal values are in (5193.6.....)InputForm[NMaximize[Availability[...],....]]Is the value for Availability different when these digits are used?I'm guessing that this difference in value is a numerical instability in the definition of Availability. Are you expecting availability to be smooth or jagged?
Posted 9 years ago
 NMaximize returns 0.999985 for T1 = 5193.6 Availability[5193.6] returns 0.999706 I am running now Table[Availability[T1], {T1, 8760}] to see which value is maximum
Posted 9 years ago
 What is the value of Availability at the point (5193.6.....) found by NMaximize? Is it the value shown by NMaximize? I'd would bet the point returned by NMaximize actually exists. The plot might not be sampled at enough intervals to show the true maximum if the function has some erratic behavior. I'd bet your problem is with Plot and not NMaximize. Plots are good tools for intuition, but they often are really deceiving.
Posted 9 years ago
 A notebook file with all the code and information to needed to duplicate the result would be the straight-forward method.Please include \$Version and its output.
Posted 9 years ago
 Sorry, I should have been more specific. Given the form of your function, the complete definition is necessary. What are all of the v, h, and sumsp functions?
Posted 9 years ago
 Availability[T1_] = (v0[T1]*h0[T1] + v1[T1]*h1[T1] + v2[T1]*h2[T1] + v3[T1]*h3[T1] + v9[T1]*h9[T1] + v10[T1]*h10[T1] + v11[T1]*h11[T1] + v12[T1]*h12[T1] + v19[T1]*h19[T1] + v20[T1]*h20[T1] + v21[T1]*h21[T1] + v22[T1]*h22[T1] + v23[T1]*h23[T1] + v29[T1]*h29[T1] + v30[T1]*h30[T1] + v31[T1]*h31[T1])/sumssp[T1]; 
Posted 9 years ago
 Prior to sending in a bug report I would think that providing the definition of your function Availability would need to be supplied. Would you share the definition of that function?
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