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some questions of optimization with minimize function in Mathcad 15

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some questions of optimization with minimize function in Mathcad 15

hi,everyone,i am a chinese,and my english is not good,this is my first time to communicate with others in english,i hope you can understand what I mean.

Now,i have a lot of problems in my work.i want to fit the experimental data using the mathcad built-in function Minimize(also,i tried Minerr).the function is known,there are 56 parameters in this function,i want to find them by making the objective function to be minimized.but when i run it,it takes a long time;also,when i change the guess value from 100 to 0,the result change as well.

So,my problems are:

1,how to reduce the time(do not change TOL or CTOL)?

2,the result must be Local optimum,and how can i find global optimum?

3,the mathcad built-in function(minimize or minerr),can i see how it works,or the inside result?

Attachment is my mathcad Calculations(mathcad 15.0)

wish for your help

my email:670442830@qq.com

thanks,my friends


parameters and constraint.pngthe objective function.pngit is very long,incomplete.the result with guess value=0.pngthe result with guess value=100.png

Chinese knot.png

3 REPLIES 3

Re: some questions of optimization with minimize function in Mathcad 15

赵亚军 wrote:

So,my problems are:

2,the result must be Local optimum,and how can i find global optimum?

3,the mathcad built-in function(minimize or minerr),can i see how it works,or the inside result?

2. You can use a genetic method:

See - http://twt.mpei.ac.ru/MAS/Worksheets/Minimum.mcd

3. You can use the tarce function:

http://twt.mpei.ac.ru/ochkov/Mathcad_14/Chapter4rus/4-39-minimum-Trace.PNG

Re: some questions of optimization with minimize function in Mathcad 15

thanks for your help

i have tried trace function ,but it is used for tracing independent variables(x,y),if i want to trace f(x,y),how to do that? i konw a stupid way,copy the independent variables(x,y),and then calculate f(x,y),but in my worksheet,the

independent variable is a matrix{9,9},it's too complex.are there any other functions that can trace f(x,y)?trace.png

Re: some questions of optimization with minimize function in Mathcad 15

I think it will be better to put your question not only here but on the Mathcad branch of this forum.

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