Bug fix: Problems with D
When a function f is defined using a second user-defined function g , D(f) doesn't work: it returns unevaluated. It does work if the function g is undefined.
Here the function f is defined using the undefined function g .
f:= x -> x + g(x); g:='g':
But now here it is after g has been defined.
> g:= x -> x^2; D(f);
What Maple looks for is a procedure named `diff/g` that performs the differentiation of g .
The command makediff(g) produces the procedure `diff/g` , allowing D(f) to work for procedures f defined using g .
The command fixD(f) applies makediff to all user-defined procedures referenced in f , thus allowing D(f) to work.
This works only for global procedures, not local procedures or module exports.
This function is part of the Maple Advisor Database.
Defining f using defined function g :
f:= x -> x*g(x^2);
g:= x -> 1 + x^2;
D(f) does not work:
Using makediff(g) to make this work:
> makediff(g); D(f);
Another function h defined using both f and g .
> h:= (x,y) -> f(x) + g(y); D(h);
Using fixD(h) to make D(h) work:
> fixD(h); D(h);
D , diff , fixD , makediff
Maple Advisor Database R. Israel, 2001