Density of rectangle and objective function in code file cook_membrane.cc

[Lance Zhang]

Hello,

If I would like to get the density of the rectangle,how should I calculate the value from rectangle in code cook_membrane.cc?

How should I design the function J(x,θ) to get the objective function J(x,θ),?This function indicates the minimum movement.θ is density of this rectangle object. 

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Conditions:Ax=b is given,A,b are known, solver x can be calculated.

I would like to get the vector of dJ/dθ=∂J/∂θ+(∂J/∂x.A^-1(θ) ){∂b(θ)/∂θ)-∂A(θ)/∂θ}.

The expression is calculated with adjoint method.

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>  

However,I didn't find the value of density in this code file ,or did I miss something?

I wish someone could provide hint or suggestions.

Thanks in advance！

Best regards

Lance

[Wolfgang Bangerth]

Lance,
you need to put more details into your questions:

> If I would like to get the density of the rectangle,how should I calculate the
> value from rectangle in code cook_membrane.cc?

What is the density, and what is the rectangle? Is the rectangle the domain?
Is the density a physical parameter in the model, or something that needs to
be computed from the solution?

You assume that we are all familiar with the contents of the file
cook_membrane, and the physical model it implements, but that is not true. The
code gallery is a collection of programs contributed by others; help us
understand your question without having to know exactly what this program
does. Assume, for example, that it is a program you wrote yourself and that
none of us know.

> How should I design the function J(x,θ) to get the objective function
> J(x,θ),?This function indicates the minimum movement.θ is density of this
> rectangle object.

The same is true here. What is J supposed to be? Is theta just a number, or a
function of x, or a function os something else? What does "minimum movement" mean?

Best
W.

--
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Wolfgang Bangerth email: bang...@colostate.edu
www: http://www.math.colostate.edu/~bangerth/