pretty-print issue in fractions

[zimmermann6]

Some symbolic fractions are not printed correctly:

sage: print z

                                  arcsin(x)
                                    -------
                                       2

One would expect the '-' bar to start under 'a' on the left.

This was found from an example in calculus.py:

sage: x = var('x')
sage: y = x^2
sage: dy = derivative(y,x)
sage: z = integral(sqrt(1 + dy^2), x, 0, 2)
sage: print z
                     arcsinh(4) + 4 sqrt(17)
                     ---------------------
                               4

Note that the actual output I get with 2.10.3 slightly differs:

sage: print z

                           arcsinh(4) + 4 sqrt(17)
                             ---------------------
                                       4

I wonder why sage -t calculus.py does not point that output difference.

CC: @burcin

Component: graphics

Issue created by migration from https://trac.sagemath.org/ticket/2531

[mwhansen]

comment:1

The issue comes from Maxima using asinh instead of arcsinh. Thus, we're simply doing a substitution in the string that Maxima returns. The testing framework doesn't catch it because it is set to ignore certain whitespace issues.

I think a good, and probably not too difficult task would be to have our own native pretty printer. I believe there is already one in Sympy that we could make use of.

[zimmermann6]

comment:2

Would it be possible to do the substitution asinh -> arcsinh within Maxima, and then calling
Maxima's pretty printer?

[mwhansen]

comment:3

I have no idea how that'd be done.

[mwhansen]

comment:5

Since we don't use Maxima's pretty-printing anymore, I'm going to close this as invalid.