## 80 Reputation

2 years, 206 days

## Need to apply to the system...

@Preben Alsholm

Thanks a lot for your kind responses. Its very helpful for me. I need to apply to the system. It does not take equal time intervals? I need to avalaute the system on time=0,0.01,0.02,0.03...10.

try.mw

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## rkf45...

@Preben Alsholm

I am trying to solve ode but the code rkf45 is not working.

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my rk-4 maple "solution := dsolve(dsys1, numeric, method = rkf45, output = listprocedure)" have little bit different result. matching 2 to 3 decimal places. Can you tell me why? can you update my proc code to rkf45 ?

## @Preben Alsholm Thanks a lot for yo...

Thanks a lot for your kind respose. Can you tell me for rk-4, this code is right, because I am getting different results

rk4 := proc(f, t, y, h) local k1, k2, k3, k4, ynew; k1 := f(t, y)*h; k2 := f(t + 1/2*h, y + 1/2*k1)*h; k3 := f(t + 1/2*h, y + 1/2*k2)*h; k4 := f(t + h, y + k3)*h; ynew := y + 1/6*k1 + 1/3*k2 + 1/3*k3 + 1/6*k4; return ynew; end proc

Thanks a lot. How can I get the value of y(t) from implicit solution using maple?

sol:=dsolve({AASnum,IC},implicit);

## How we can convert?...

@dharr
Thanks a lot for yout reply.
yt := y(t) = RootOf(8*t - 4*ln(_Z + 1) + 2*ln(_Z^2 + 1) - 4*arctan(_Z) + 2*ln(2) + Pi)

Can we convert it normal solution?

## Uploaded the real code for better sugges...

Dear Professor;

Hope you are fine. You are absolutly right Professor. Maple builton commands are always better and I always like it. In my situation, when i increase the value of "N", number of nonlinear ODE's increased and further builton comand take a lot of computational time to evaluate the solution. But my target is reduce the computation cost. I have upload the real code. I have two generlized ODE's and further with the help of loops and discritization on different points with value of "N", i obtained system of nonlinear ODE's and further i need to solve with the help of RK-4. For better accuracy, I need to increase "N" which increse the number of nonlinear ODE's. Kindly visit my real code and help me further. I am waiting for your kind response.

Thanks

## Is that Possible to Make Code...

Dear Professor;

Thanks a lot for this. I cannot use builton command beacuse system of ODE's increase as i will increase the value of "N". Therefore this command will creat heavy computational cost. Is that possible to make code not builton command? I am waiting for your kind response.

Thanks

## First One Each...

Thanks a lot. It helps me a lot. Can it take first ODE of each variable ?

## Z_0(t) is extra...

Professor Z_0(t) is extra which i have removed and update the data and file accordingly. Z_1(t) and Z_2(t) is not extra, it contaion odes and part of the system of ODE's. System is nonlinear due this constants. Without this system become linear which can easily handle with mentioed command but i need to convert system of nonlinear ODE's to matrixcs.

## matrix formulation of nonlinear ODE's...

@Rouben Rostamian

Yes Professor.

I need matrix formulation of nonlinear ODE's. Is that any solution?

## Solve Comand Issue...

Dear Professor;

Thanks a lot for your response. Saperately it is solving but not collectively. I need to find the solution in term of other variable. Not possible to find?

## File Name Updated...

Thanks a lot Professor. I have updated the file name according to your instruction. Now it is ok. Thnaks a lot for your response.

I have uploded the file properly but i donot know why maple file download is showing error.