[Maxima] substituting function in diff

[David Webb]

On Tuesday 14 July 2009 18:24:59 Stavros Macrakis wrote:
> I'm not sure I understand your whole problem, but have you taken a look at 
substpart?
> 
> You can do things like
> 
> substinpart( myfavoritefunction( piece ) , expr, 2, 2, 1 )
> 
> which extracts inpart(expr,2,2,1), calls your function on it, and returns an 
expression with the value in place of the original subexpression.

Many thanks - this is just what I wanted.  I thought I had read all the 
relevant bits of the manual but ... .  I had also tried '?? replace' but 
not '?? inpart'!

Regards,

David Webb.