odesolve problem

[ptc-4386097]

Hi

I am a new user of Mathcad, so my first step was to read and used the tutorial, but when I arrived at the "task 3-3" in the solving tutorial i can't do it, in the solve block Odesolve did not work. I try to put the units and the correct labels but there is a problem with the "initial conditions". I put my worksheet for any one who can help me.

thks Claude

[ValeryOchkov]

Check you units please. See my try in attach.

[ptc-4386097]

Valery

you were right for the init of u(t) (the oscilating force). but that doesn't solve the problem with Odesolve, I try to solve a 1 order ODE with odesolve, no problem it's only need one initial condition, but when I try a simple second order ODE like : my''(x)+ky(x)=0 ( a simple harmonic oscilator ) same problem with the initial conditions, odesolve needs now two initial conditions.

Claude

[ptc-4386097]

Valery

one more thing, the worksheet you post, doesn't work in my Mathcad, is it possible that my Mathcad configuration is wrong? ( I am in S.I system)

Claude

[ValeryOchkov]

I think the problem is in Mathcad Prime.

See the solution in Mathcad 15:

[ptc-4386097]

Valery

Thanks, I also think it's mathcad prime (or just the funtion odesolve), I try a lot 2 order ODE like SMH,pendulum, RLC ...nothing work and show the same problem.

When I use AdamsBDF it works fine. But it's strange because there is a lot of exemples in mathcad-help using odesolve in a solve block. If they are there, they are suposed to work!!!.

thanks any way

Claude

[ValeryOchkov]

Claude toto wrote:

I also think it's Mathcad Prime (or just the funtion odesolve)

Yes!

Try please to change ...=N into N=... in the Solve-Block of this task bellow and you have got same error!

We say in such cases - the best (Mathcad Prime, ODE with units) is an enemy of good (Mathcad 11)!

[ptc-4386097]

In deed, but if you put back the highest derivative order on the left living only the velocity on the right it's work again, very strange! At least we learn something: always let the highest derivative on the left side!

Valery, is it possible to have mathcad 15 (or 14) and prime installed together on the same computer?

Claude

[VladimirN]

Claude toto wrote:

...is it possible to have mathcad 15 (or 14) and prime installed together on the same computer?...

Yes, is possible. You can install on one computer as a version of Mathcad 15 and version Mathcad Prime 1.0 (the same license file can be used to activate both versions). Also, Mathcad 15 is required for converting files from previous versions of Mathcad in the new format ".mcdx" for Mathcad Prime.

Download trial versions of programs here:

Mathcad Prime 1.0: http://www.ptc.com/products/mathcad/mathcad-prime-1-0/free-trial.htm

Mathcad 15.0: http://www.ptc.com/products/mathcad/mathcad-15-0/free-trial.htm

[ptc-4386097]

ok thanks

In MathCad 15 the symbolic calculation is still present, isn't it?

Claude

[ValeryOchkov · Accepted solution]

Claude toto wrote:

ok thanks

In MathCad 15 the symbolic calculation is still present, isn't it?

Claude

Present!

[VladimirN]

Yes. And for Mathcad Prime symbolic calculation will be presented in version 2.0 (release is scheduled for Q1 2012).

[ValeryOchkov]

Valery, is it possible to have mathcad 15 (or 14) and prime installed together on the same computer?

Claude

Every self-respecting intellectual must have on your desk:

[ValeryOchkov]

Claude toto wrote:

In deed, but if you put back the highest derivative order on the left living only the velocity on the right it's work again, very strange! At least we learn something: always let the highest derivative on the left side!

Valery, is it possible to have mathcad 15 (or 14) and prime installed together on the same computer?

Claude

Press please the button "Correct answer!"