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May 27, 2020
05:10 PM

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May 27, 2020
05:10 PM

Odesolve Too few initial conditions

Hello,

I'm trying to recreate a student's work presented in a paper and I just can't seem to get it to work. I've gone through as many of the posts here on this issue as I can but don't see many of the common errors (incorrect equal sign etc). Occasionally i'll see a stray typo and fix it, but I think may have been staring at this too long to see what's wrong with it.

Error message is "Too few initial conditions". Mathcad doesn't seem very flexible in trying to track down erros like this.

I really appreciate your time and assistance,

- T

Solved! Go to Solution.

ACCEPTED SOLUTION

Accepted Solutions

May 27, 2020
05:38 PM

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May 27, 2020
05:38 PM

You have initial conditions for V.P and V.T,

but you have a derivative for V(t),

that's not V.T(t) and not V.P(t)...

Besides that, you don't have an initial condition for V.p(t)...(That's lower case p here).

I suppose you deliberately disabled the first equation with the derivative of Z(t) ...

Success!

Luc

5 REPLIES 5

May 27, 2020
05:38 PM

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May 27, 2020
05:38 PM

You have initial conditions for V.P and V.T,

but you have a derivative for V(t),

that's not V.T(t) and not V.P(t)...

Besides that, you don't have an initial condition for V.p(t)...(That's lower case p here).

I suppose you deliberately disabled the first equation with the derivative of Z(t) ...

Success!

Luc

May 27, 2020
06:11 PM

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May 27, 2020
06:11 PM

Thanks for catching that! That explains it, was driving me nuts.

Now onto researching the next error, "The return value of this function must match the problem size."

Thanks for the help!

May 28, 2020
02:41 AM

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May 28, 2020
02:41 AM

See if you have accidentally used array notation instead of a literal subscript (Typed a "[" instead of a ".").

Success!

Luc

May 28, 2020
02:57 AM

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May 28, 2020
02:57 AM

It was an issue with the odesolve's intvls value being too large, it wouldn't find a solution until reduced to a smaller value.

Thanks for all your help.

May 28, 2020
03:20 AM

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May 28, 2020
03:20 AM

Your welcome.

Success with your work!

Luc