Solving Maple Procedure Problem with DE_soln

[Warr]

Having a problem with a procedure in maple

the procedure is

> proc1:=proc(f,a,b,xmin,xmax)
> local locallist;
> locallist:=[seq(rhs(f),_C1=a..b)];
> RETURN(locallist);
> end;

the test function I am using for f is

DE_soln = y(x) = (arctan(x)+_C1)/(1+x^2)^2;

Which I got from using the dsolve for a differential equation

When I generated a sequence of this externally (not using the procedure)

with the following command

DE_soln_list := [seq(rhs(DE_soln),_C1=-2..2)];

I got a set of 5 solutions with just had the _C1 replaced by -2,-1,0,1,2 in each respective 'solution'

When I try plugging DE_soln into the procedure, it returns a list of 5 solutions, but all in the form (arctan(x)+_C1)/(1+x^2)^2

_C1 was simply a variable created by dsolve when solving the differential equation.

How do I get the procedure to sub in the numbers for _C1, because it seems that it works differently inside the procedure (I tried to declare _C1 as a local variable inside the procedure but that did nothing)

thanks

 

[mmwave]

Thank you for bringing this issue to our attention. It seems that the procedure is not properly substituting the values for _C1 in the list. This could be due to the fact that _C1 is not explicitly defined as a local variable in the procedure.

To fix this issue, you can try declaring _C1 as a local variable within the procedure, using the following command:

local _C1;

This should allow the procedure to properly substitute the values for _C1 in the list. If this does not work, you can also try using the "subs" command to substitute the values for _C1 in the list, before returning it.

I hope this helps resolve your issue. If you continue to experience problems, please don't hesitate to reach out for further assistance. Happy computing!

 

[tacman]

It seems like the issue may be with how you are calling the procedure. In your test function, you are using "DE_soln" as the input for the procedure, which is just a symbolic expression and not a function with a specific value for _C1. This is why the procedure is returning the same expression for each solution, as it is not able to substitute in a specific value for _C1.

To fix this, you could modify your test function to include a specific value for _C1, such as:

DE_soln := y(x) = (arctan(x)+1)/(1+x^2)^2;

This way, when you call the procedure, it will use this specific value for _C1 and return the correct solution. Alternatively, you could also modify the procedure to take in a specific value for _C1 as an additional input, rather than trying to declare it as a local variable within the procedure.

I hope this helps and resolves your issue with the procedure. If you continue to encounter any problems, please provide more details and I would be happy to assist further.