Help with Mathcad Rkadapt function

In summary, the conversation is about using the Rkadapt function in Mathcad 13 and experiencing an error message. The problem has been resolved by starting a new worksheet and rewriting the function.
  • #1
Natty727
3
0

Homework Statement



I'm trying to use the rkadapt function in mathcad 13 but it's coming up in red and telling me 'This function cannot be used here'. Not really sure why because all the constants used have been defined above it and take sensible values. The values of x1 and x2 have been defined in the matrix x. If anyone can help me with this that would be great! :cool:

Homework Equations



[PLAIN]http://server3.uploadit.org/files/nattyuk-Rkadapt3.JPG

The Attempt at a Solution



[PLAIN]http://server3.uploadit.org/files/nattyuk-Rkadapt3.JPG
 
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  • #2
Hello!

I have the same problem... Natty, did you find an answer to the problem?
(I have used the Rkadapt function in Mathcad 2000 and it worked just fine, but in Mathcad 13 i don;t know what the problem is :( ...)

Thx!
 
  • #3
Hey johnny, I've got mine working now but I still don't know what was wrong with it originally! I started a new worksheet and re-wrote it which seemed to do the trick, not sure why because all the positioning and declarations were exactly the same... Sorry I can't provide a more helpful answer!
 

FAQ: Help with Mathcad Rkadapt function

1. What is the purpose of the Rkadapt function in Mathcad?

The Rkadapt function in Mathcad is used for numerical integration of differential equations. It uses the adaptive Runge-Kutta method to provide a more accurate solution compared to other integration methods.

2. How do I use the Rkadapt function in my Mathcad worksheet?

To use the Rkadapt function, you need to first define your differential equation in Mathcad. Then, insert the Rkadapt function and input the necessary parameters such as the initial conditions, integration step size, and error tolerance. Finally, the Rkadapt function will solve and display the solution to your differential equation.

3. What is the difference between Rkadapt and other integration functions in Mathcad?

The Rkadapt function uses the adaptive Runge-Kutta method, which adjusts the integration step size based on the error tolerance specified by the user. This results in a more accurate solution compared to other integration functions, such as the Euler or Simpson's rule, which use a fixed step size.

4. Can the Rkadapt function handle stiff differential equations?

Yes, the Rkadapt function is designed to handle stiff differential equations. It uses a variable step size to adapt to the changing behavior of the solution, making it more efficient in solving stiff problems compared to other integration methods.

5. Is there a limit to the number of differential equations that can be solved using the Rkadapt function?

No, there is no limit to the number of differential equations that can be solved using the Rkadapt function. However, the accuracy and efficiency of the solution may be affected if the system of equations is large and complex. In such cases, it is recommended to split the equations into smaller systems and solve them separately.

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