simon-git: spigot (master): Simon Tatham

[Commits to Tartarus hosted VCS]

TL;DR:
  de30d90 Expose Spigot::is_rational() in the Python API.
  5c2225e Fix an obvious goof in mkintspig.
  726a32b Python code: fix some careless uses of None.
  652f64b powbegin: permit a non-integer value of a.
  8d56ccc powbegin: support a constant multiplicative factor.

Repository:     https://git.tartarus.org/simon/spigot.git
On the web:     https://git.tartarus.org/?p=simon/spigot.git
Branch updated: master
Committer:      Simon Tatham <anakin at pobox.com>
Date:           2017-08-31 08:33:50

commit de30d907bc146efb0a6ce5d58e187ab167870459
web diff https://git.tartarus.org/?p=simon/spigot.git;a=commitdiff;h=de30d907bc146efb0a6ce5d58e187ab167870459;hp=32b73a48e30882f0e5a0cfae6ac932c9593b2571
Author: Simon Tatham <anakin at pobox.com>
Date:   Thu Aug 31 07:18:06 2017 +0100

    Expose Spigot::is_rational() in the Python API.
    
    In Python, of course, we don't have to faff about with a boolean
    return value and writable reference parameters; the return value is
    simply an (n,d) tuple or None.

 python/pyspig.cpp       | 19 +++++++++++++++++++
 python/spig/__init__.py |  3 +++
 2 files changed, 22 insertions(+)

commit 5c2225e6ade8988abf05fa776e1b103038e3efe8
web diff https://git.tartarus.org/?p=simon/spigot.git;a=commitdiff;h=5c2225e6ade8988abf05fa776e1b103038e3efe8;hp=de30d907bc146efb0a6ce5d58e187ab167870459
Author: Simon Tatham <anakin at pobox.com>
Date:   Thu Aug 31 08:23:14 2017 +0100

    Fix an obvious goof in mkintspig.
    
    You can't pass an outer Python spigot object to the inner
    C++ clone method.

 python/spig/__init__.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

commit 726a32b7a2090a6086fcb3f02e3f4bafd1a00199
web diff https://git.tartarus.org/?p=simon/spigot.git;a=commitdiff;h=726a32b7a2090a6086fcb3f02e3f4bafd1a00199;hp=5c2225e6ade8988abf05fa776e1b103038e3efe8
Author: Simon Tatham <anakin at pobox.com>
Date:   Thu Aug 31 08:24:36 2017 +0100

    Python code: fix some careless uses of None.
    
    Testing against None should be done with 'is', not '=='. Also, the
    check of scope against None in Spigot.__init__ was totally spurious.

 python/powbegin.py      | 6 +++---
 python/spig/__init__.py | 2 +-
 2 files changed, 4 insertions(+), 4 deletions(-)

commit 652f64bdb1c509caa6f540575e143841b95ff2af
web diff https://git.tartarus.org/?p=simon/spigot.git;a=commitdiff;h=652f64bdb1c509caa6f540575e143841b95ff2af;hp=726a32b7a2090a6086fcb3f02e3f4bafd1a00199
Author: Simon Tatham <anakin at pobox.com>
Date:   Thu Aug 31 08:26:23 2017 +0100

    powbegin: permit a non-integer value of a.
    
    Now you can ask, for example, whether there's a power of pi or e or
    phi that begins with particular digits.

 python/powbegin.py | 26 ++++++++++++++++++++++++--
 1 file changed, 24 insertions(+), 2 deletions(-)

commit 8d56cccabfd246f8ec534a0400b263db371fae00
web diff https://git.tartarus.org/?p=simon/spigot.git;a=commitdiff;h=8d56cccabfd246f8ec534a0400b263db371fae00;hp=652f64bdb1c509caa6f540575e143841b95ff2af
Author: Simon Tatham <anakin at pobox.com>
Date:   Thu Aug 31 08:27:05 2017 +0100

    powbegin: support a constant multiplicative factor.
    
    Now you can ask for an integer n such that a^n * f begins with given
    digits. For example, you can set a=phi and f=1/sqrt(5), which will
    tell you whether phi^n/sqrt(5) begins with given digits. (Which, up to
    small errors at interval ends due to the (-1/phi)^n term in Binet's
    formula, is _nearly_ always the same as saying that the nth Fibonacci
    number begins with those digits.)
    
    For example, the command
      powbegin.py -M '1/sqrt(5)' phi 1234
    delivers the result 1629, which strongly suggests (but doesn't _quite_
    prove by itself) that F_1629 starts with the digits 1234, and indeed
    if you evaluate it by hand, it does indeed.

 python/powbegin.py | 29 +++++++++++++++++++----------
 1 file changed, 19 insertions(+), 10 deletions(-)