Simplify 1//1

[s-celles]

Hello,

This could probably be simplified

julia> taylor(exp(x), x, 0:3)
(1//1) + x + (1//2)*(x^2) + (1//6)*(x^3)

to

1 + x + (1//2)*(x^2) + (1//6)*(x^3)

Regards

[ChrisRackauckas]

What happens if you call simplify on it?

[s-celles]

julia> using Symbolics

julia> @variables x
1-element Vector{Num}:
 x

julia> expr = taylor(exp(x), x, 0:3)
(1//1) + x + (1//2)*(x^2) + (1//6)*(x^3)

julia> simplify(expr)
(1//1) + x + (1//2)*(x^2) + (1//6)*(x^3)

[AayushSabharwal]

We don't simplify constants.

[s-celles]

Most others CAS do simplify or at least don't show results like so. Why not doing so?

[AayushSabharwal]

By default, SU will keep the expression as true to user input as possible. There are use cases where it is beneficial to keep the rational form. If we change this to print differently (i.e. print 1 even if it stores 1//1) that effectively lies to the user and can lead to difficult bugs. At best, simplify could be made to simplify such constants.

[s-celles]

I'm clearly in favor of a simplify function which, by default, behave this way ie simplify rational with 1 as denominator.

[hersle]

For this particular example, taylor already gives the integer form (on Symbolics 7.8.0)?

julia> @variables x
1-element Vector{Num}:
 x

julia> taylor(exp(x), x, 0:3)
1 + x + (1//2)*(x^2) + (1//6)*(x^3)

The general simplification case is another discussion, of course.