Waldek,

What specifically implements the numeric evaluation in the example of

NV(x:Float):Float == ... erf(...)  ?

On 2015-10-22 6:26 PM, "Waldek Hebisch" <[email protected]> wrote:
>
> expressions in undesirable way.  So I would like to limit
> automatic evaluation only to few cases when it is clear
> that it will cause no problems.

Do you mean all automatic evaluations, only those involving retractions to
the coefficient domain, or only those that result in "numeric
approximations"?

>
> OK, above I gave reasons while I am not eager to follow Axiom
> there.  So what I intend to do?  My current plan is to add
> new property to operators,  giving appropriate evaluation
> function.  Then numeric could be implemented as a tree
> walker over expressions, in the style of 'eval'.
>

Should there be one evaluation function for each possible numeric domain or
something more generic? Evaluation functions for many operators already
exist.  Either way this sounds awkward to me.

It seems to make fairly good sense to me that one should avoid coefficient
domains for Expression that export functions that implement otherwise
symbolic operators if one does not want such automatic simplifications.
This is the essential difference between Expression Float and Expression
Integer.

Bill Page.

-- 
You received this message because you are subscribed to the Google Groups 
"FriCAS - computer algebra system" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/fricas-devel.
For more options, visit https://groups.google.com/d/optout.

Reply via email to