Upgrade to pynac-0.7.22

[rws]

In the new version:

• fix matching
• fast and working versons of quo_rem and rational decomposition
• fix power inconsistency
• internal fix of another power inconsistency (Sage 25639)
• (x^a)^b --> x^(ab) IF x real, a odd integer, ab integer
• add ex::treesize() as complexity metric
• information for packagers

• implement commutative matching; fix GiNaC's matching deficiencies (#25168)
• substitute patternless if no wildcards present
• remove some compiler warnings
• update AX_CXX_COMPILE_STDCXX.m4

• fix exp(c*f(x)) simplification
• fix cases(...).subs(...)
• function::info for min/max_symbolic(#21945)
• performance and readability improvements

• correct sinh/cosh/tanh return type (#24299)
• atan2 fixes
• potential memleaks fixed
• fixes in Giac interface
• subs can now substitute numeric terms (#23964)

• fix memleak in in-place PyObject numerics (#24745)
• fix endless computation (#24883)
• Python interface / Py3 fixes and improvements (thx Erik Bray, #24561, #24752, #24522)
• fix internal asin/acos of complex balls
• draw factors out of add^rational (#24768, #25251, #25252)
• exp(f(x)), exp(c*f(x)), f inv. hyperbolic simplifications (#24841)
• always extend trig/hyperbolic functions to complex domain (#24428)
• extensive code readability improvements

​https://github.com/pynac/pynac/releases/download/pynac-0.7.22/pynac-0.7.22.tar.bz2

[rws]

New commits:

​e470685	version / chkum / rm patch
​d3511ce	24838: doctest fixes

[jdemeyer]

Just a question: is this supposed to fix #24522 too?

[rws]

Yes, that PR is merged. I'll probably add a hotfix for #24883 here as patch, too.

[jdemeyer]

Replying to rws:

I'll probably add a hotfix for #24883 here as patch, too.

Then I'm setting this to needs_work. If you change your mind, feel free to set this back to needs_review.

[rws]

The issue is no longer there. Please review.

[jdemeyer]

This used to return a purely imaginary number, now there is a small real part:

sage: arccosh(x).subs(x=0.9)
-9.66146955461936e-22 + 0.451026811796262*I

[rws]

This is an artifact of conversion to CC:

sage: CC(ComplexBallField(68)(0.9).arccosh())
-9.66146955461936e-22 + 0.451026811796262*I

We use arb with precision+15 and convert back to parent, all to make up for missing or limited (in the calculus sense, not the algebraic, note recent discussion) member functions of parent (RR in this case). Before this pynac version we had specific logic to zero the real part but this was error-prone. IMHO CC conversion of complex balls should be fixed.

[rws]

See also ​https://github.com/fredrik-johansson/arb/issues/198

[rws]

You may also want to know why I'm using arb and not mpfr:

sage: r=srange(-2.5,2.5,.01)
sage: rr = [CC(i) for i in r]
sage: %timeit for x in rr: _=x.arccosh()
100 loops, best of 3: 11.9 ms per loop
sage: rr = [CBF(i) for i in r]
sage: %timeit for x in rr: _=x.arccosh()
1000 loops, best of 3: 649 µs per loop

[rws]

What do you prefer, patching arb or the arb interface?

[rws]

See ​https://github.com/fredrik-johansson/arb/pull/210

[jdemeyer]

Replying to rws:

You may also want to know why I'm using arb and not mpfr:

Despite what you think, you are not using mpfr, but PARI:

    def arccosh(self):
        """
        Return the hyperbolic arccosine of ``self``.

        EXAMPLES::

            sage: (1+CC(I)).arccosh()
            1.06127506190504 + 0.904556894302381*I
        """
        return self._parent(self.__pari__().acosh())

If you want to compare with something, it should be mpc (in Sage: CC = MPComplexField(53))

[rws]

Interestingly,

sage: arccosh(x).subs(x=MPComplexField(53)(0.9))
...
TypeError: no canonical coercion from Complex Field with 53 bits of precision to Symbolic Ring

[rws]

Replying to rws:

See ​https://github.com/fredrik-johansson/arb/pull/210

This is now merged. Do we want that patch in this ticket? If not, anything else?

[git]

Branch pushed to git repo; I updated commit sha1. New commits:

​e85fa6c	Merge branch 'develop' into t/24838/upgrade_to_pynac_0_7_17
​9f86eb7	24838: pynac-0.7.18 doctest fixes

[rws]

New release incoming.

[git]

Branch pushed to git repo; I updated commit sha1. New commits:

​ae5eac7

24838: version/chksum

[rws]

0.7.17 introduced a bug in exp(ex*log(x)) simplification, and we need a new release, anyway.

[git]

Branch pushed to git repo; I updated commit sha1. New commits:

​79d54ea	Merge branch 'develop' into t/24838/upgrade_to_pynac_0_7_17
​75b2f85	fix doctests
​8878283	24838: version/chksum

[jdemeyer]

This looks fishy:

-            sage: SR(CDF(1/2)).arccosh()  # rel tol 1e-15
+            sage: SR(CDF(1/2)).arccosh() # abs tol 1e-15

[jdemeyer]

The analogous thing as 9 should be fixed for pure imaginary results:

sage: CDF(1/2).arccosh()
1.0471975511965979*I
sage: SR(CDF(1/2)).arccosh()
-6.372599439108525e-21 + 1.0471975511965979*I

Then you also revert 29

[rws]

Replying to jdemeyer:

The analogous thing as 9 should be fixed for pure imaginary results:

sage: CDF(1/2).arccosh()
1.0471975511965979*I
sage: SR(CDF(1/2)).arccosh()
-6.372599439108525e-21 + 1.0471975511965979*I

As explained in 10 missing FP functionality is gained using arb. But there was that bug in arb which is now fixed. Consequentially we need that fix or a recent arb to get the right result, see 14.

Then you also revert 29

Will re-revert.

[rws]

I confirm that this works with ​https://github.com/fredrik-johansson/arb/commit/7afd3bfaf1697739751d96d3665ef83e78c76820 applied, which is in arb-2.13.0 (#24927).

[git]

Branch pushed to git repo; I updated commit sha1. New commits:

​8a2217a	Merge branch 'develop' into t/24838/upgrade_to_pynac_0_7_17
​3efba1a	fix doctest

[rws]

Some recent Sage commit makes doctests (involving powers of I) fail together with pynac-0.7.17 so we'll need a fix in 0.7.20.

[rws]

Actually it's not our fault: #25458.

[git]

Branch pushed to git repo; I updated commit sha1. New commits:

​ed36070	Merge branch 'develop' into t/24838/upgrade_to_pynac_0_7_17
​3278103	Merge branch 'develop' into t/24838/upgrade_to_pynac_0_7_17
​ca69aef	Merge branch 'develop' into t/24838/upgrade_to_pynac_0_7_17
​97bf3b7	24838: doctest fixes
​e6b01df	doctest fix
​fdb4210	Merge branch 'develop' into t/24838/upgrade_to_pynac_0_7_17
​ad07cd5	24838: 0.7.20 version/chksum