Re: [Maxima-discuss] integrate_use_rootsof question, was: How can I catch this error? "errcatch" doesn't do the trick.

[David S. <d.s...@go...>]

Hi Robert,

> Is there another way to inhibit the unwanted substitution? I think it's
> better to keep the rootsof(...) expression in terms of the variable of
> integration -- otherwise we would need to add a notation to rootsof to
> indicate what the variable is. Also it might (or might not) look
> unfamiliar to users.

In the SourceForge bug report, I added another suggestion, which is to use
the same dummy variable in the "rootsof" argument. This is also how Wolfram
Alpha does it (their "%r1" is "omega" - it appears below the summation sign
and also in the "log" expression). In my view, it would be the same obvious
as when using the variable of integration.

But you're right, there is a mathematical ambiguity - especially when the
integrand contains additional constants, then we'd get something like
"rootsof(a*%r1^3+b*%r1+c)".

Overall, I'd vote for giving "rootsof" a second argument, then it would be
perfectly clear and unambiguous. "rootsof" could then theoretically even be
replaced with a nounified "solve", since it assumes "= 0" if the expression
given to it is not an equation.

What do you think?

And do you know of other places Maxima where "rootsof" is used (so those
would have to be changed as well), or is it only used in integration?

> If you have a Sourceforge user name, I will gladly add it to the list of
> developers.

Sure, it's "tomasriker". Thank you, it's a great honor!

Best regards,
David