Solver Mathcad 15 and Mathcad Prime

[ValeryOchkov]

I have not any solution in Mathcad 15. The problem about catenary with potential energy.

I have convert the sheet in Prime 3.1 - now I have solution!

New solver is more powerful! Or?

And second - how is i:=1..n in solve block?

[ValeryOchkov]

Fine?

[RichardJ]

The new solver is the "Knitro" solver. They (Knitro) of course claim it's better, but I have seen it fail where good old Levenberg-Marquardt worked, so I would just say that it's different.

[ValeryOchkov]

Richard Jackson написал(а):

The new solver is the "Knitro" solver

Yes - see Artelys | Optimization solutions - Page d'accueil

n=25! What is the max n for Knitro ? Work please with attach!

[ValeryOchkov]

Verify for n=25 masses

[ValeryOchkov]

How to create a parabola

[ValeryOchkov]

Parabola and Catenary at same S!

Great Galileo thought that the chain is slack on the parabola!

[-MFra-]

Why, then, let pass variables with subscript, for elements of a vector?

[ValeryOchkov]

Sorry, but all is OK!

x0, y0, xn+1 and yn+1 are x.0, y.0, x.n+1 and y.n+1 not x[0, y[0, x[n+1 and y[n+1

[ValeryOchkov]

We, here in Italy, we say that you have done a nice .... catenary  (see picture)

[-MFra-]

Please excuse me, I just wanted to say that this work seems to me a pastiche.... (as was depicted in the picture that I deleted)

FM

[ValeryOchkov]

[AlvaroDíaz]

Hi. Attached seems to work fine when masses are uniformly distributed, but I'm not convinced enough when the chains are varying.

Best regards.

Alvaro.

[AlvaroDíaz]

Hi Valery.

Some other few modifications. It's a hard problem, have a lot of variations. Can't found my Elgotz to check what he says about this variational calculus.

Best regards.

Alvaro.

[ValeryOchkov]

Thanks, Alvaro!

The problem is so.

I have in the Solver

but I want to have so

But it is not possible in Mathcad 15 and Prime.

[AlvaroDíaz]

Yep, I know.

In the attached, instead of the summatorie, which give scalar result, in the solve block there are vectorial restrictions, introducing a Delta function, which is the diff function in matlab. So, you have in some way what you ask: a lot of equations in the solve block, but without writing them one by one.

Notice that the poor results, reflected in the Potential Energy values, are problem of the Mathcad solver, maybe in prime, with the knitro solver can get better results.

Also shows that in a Given-Find block, you can use range variables, but with some limitations. At the end an example of that.

Best regards.

Alvaro.

[ValeryOchkov]

Two cannot!

We cannot insert the Solve Block in a program

We cannot insert a program in the Solve Block

Do you know a 3-d "cannot"?

[MJG]

We cannot insert the Solve Block in a program

I haven't been following this thread, so I'm not exactly sure what you're trying to accomplish, but I don't think this statement is accurate.  Can't you write a solve block as a function and call that function in a program?

We cannot insert a program in the Solve Block

Similarly, can't you write the program as a function and insert the function into a solve block?

[ValeryOchkov]

Mark Gase написал(а):

We cannot insert the Solve Block in a program

I haven't been following this thread, so I'm not exactly sure what you're trying to accomplish, but I don't think this statement is accurate.  Can't you write a solve block as a function and call that function in a program?

Thanks, I know it and use it. But we can not insert the Given keyword and the Find/MinErr function in programs

>>We cannot insert a program in the Solve Block

>Similarly, can't you write the program as a function and insert the function into a solve block?

Try please do it in this problem - see above.