Skip to main content
赵
赵亚军1-Visitor
1-Visitor
February 15, 2012
Question

some questions of optimization with minimize function in Mathcad 15

  • February 15, 2012
  • 1 reply
  • 5062 views

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

1 reply

V
ValeryOchkov24-Ruby IV
24-Ruby IV
February 15, 2012

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

赵
赵亚军1-VisitorAuthor
1-Visitor
February 16, 2012

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

V
ValeryOchkov24-Ruby IV
24-Ruby IV
February 16, 2012

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

Terms & ConditionsAccessibility statement