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GeezerVison is showing github.com — bpo-41513: Improve order of adding fractional values. Improve variable names. by rhettinger · Pull Request #22368 · python/cpython

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@rhettinger

@rhettinger rhettinger commented Sep 23, 2020 •
edited by bedevere-bot
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Improve the variable names and optimize the order that the fractional components are added together. Gives a slight improvement in speed and a minor improvement in accuracy.

Baseline timing:

$ pytime -s 'from math import pi, hypot, e, tau' 'hypot(pi, e)'
5000000 loops, best of 11: 83.6 nsec per loop
$ pytime -s 'from math import pi, hypot, e, tau' 'hypot(pi, e, tau)'
5000000 loops, best of 11: 89.1 nsec per loop
$ pytime -s 'from math import pi, hypot, e, tau' 'hypot(pi, e, tau, e)'
5000000 loops, best of 11: 98.4 nsec per loop

Timing with PR:

$ pytime -s 'from math import pi, hypot, e, tau' 'hypot(pi, e)'
5000000 loops, best of 11: 83.1 nsec per loop
$ pytime -s 'from math import pi, hypot, e, tau' 'hypot(pi, e, tau)'
5000000 loops, best of 11: 89.1 nsec per loop
$ pytime -s 'from math import pi, hypot, e, tau' 'hypot(pi, e, tau, e)'
5000000 loops, best of 11: 96 nsec per loop

Accuracy tests. n is the number of dimensions followed by the weighted average number of correct bits (higher is better). The list contains counts for number of bits of error (lower counts are better). hypot12 is the baseline and hypot15 is the new code:

n=2 108.94  hypot12 [(104, 465), (105, 9650), (106, 74210), (107, 177328), (108, 220778)
n=2 109.12  hypot15 [(104, 76), (105, 6170), (106, 65987), (107, 163375), (108, 206841)

n=3 108.48  hypot12 [(103, 8), (104, 486), (105, 13420), (106, 93712), (107, 229769), (108, 243386)
n=3 108.72  hypot15 [(104, 102), (105, 7086), (106, 82426), (107, 208486), (108, 230416)

n=5 108.17  hypot12 [(103, 11), (104, 1353), (105, 18261), (106, 123382), (107, 253589), (108, 250362)
n=5 108.40  hypot15 [(104, 174), (105, 10427), (106, 108216), (107, 232246), (108, 243693)

n=10    107.97  hypot12 [(103, 33), (104, 3417), (105, 33754), (106, 150365), (107, 261133), (108, 237118)
n=10    108.18  hypot15 [(103, 5), (104, 653), (105, 24797), (106, 132075), (107, 243443), (108, 238205)

n=20    107.92  hypot12 [(102, 1), (103, 193), (104, 3811), (105, 39405), (106, 153847), (107, 263381), (108, 234462)
n=20    108.10  hypot15 [(103, 59), (104, 2030), (105, 29794), (106, 136819), (107, 247027), (108, 238805)

n=50    107.69  hypot12 [(103, 57), (104, 4987), (105, 53502), (106, 188830), (107, 275831), (108, 217911)
n=50    107.80  hypot15 [(103, 97), (104, 4406), (105, 47363), (106, 175900), (107, 265514), (108, 223802)

n=100   107.29  hypot12 [(103, 397), (104, 14872), (105, 101681), (106, 240449), (107, 264715), (108, 178790)
n=100   107.33  hypot15 [(103, 615), (104, 18598), (105, 100409), (106, 228175), (107, 258464), (108, 183213)

n=200   106.62  hypot12 [(102, 19), (103, 4065), (104, 55179), (105, 204706), (106, 282193), (107, 210798), (108, 119011)
n=200   106.60  hypot15 [(102, 31), (103, 5541), (104, 59552), (105, 205935), (106, 278179), (107, 208483), (108, 118478)

n=1000  104.68  hypot12 [(100, 102), (101, 5593), (102, 57169), (103, 184363), (104, 276279), (105, 218668), (106, 126077)
n=1000  104.64  hypot15 [(100, 119), (101, 5805), (102, 60339), (103, 193004), (104, 276688), (105, 213714), (106, 122384)

# Case for very large n but with fewer trials:

n=10000 100.49  hypot12 [(96, 62), (97, 1261), (98, 8502), (99, 20909), (100, 25938), (101, 19875), (102, 11594)
n=10000 100.48  hypot15 [(96, 61), (97, 1271), (98, 8530), (99, 20922), (100, 26032), (101, 19856), (102, 11562)

n=50000 97.72   hypot12 [(93, 5), (94, 521), (95, 5593), (96, 18338), (97, 26766), (98, 22070), (99, 12926)
n=50000 97.72   hypot15 [(93, 5), (94, 531), (95, 5582), (96, 18319), (97, 26805), (98, 22049), (99, 12970)

https://bugs.python.org/issue41513

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@rhettinger
Improve order of adding fractional values. Improve variable names.
7148a38
@rhettinger rhettinger added the skip news label Sep 23, 2020
@the-knights-who-say-ni the-knights-who-say-ni added the CLA signed label Sep 23, 2020
@bedevere-bot bedevere-bot added the awaiting core review label Sep 23, 2020
@rhettinger rhettinger added 🔨 test-with-buildbots Test PR w/ buildbots; report in status section and removed awaiting core review labels Sep 23, 2020
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bedevere-bot commented Sep 23, 2020

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🤖 New build scheduled with the buildbot fleet by @rhettinger for commit 7148a38 🤖

If you want to schedule another build, you need to add the ":hammer: test-with-buildbots" label again.
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@bedevere-bot bedevere-bot removed the 🔨 test-with-buildbots Test PR w/ buildbots; report in status section label Sep 23, 2020
@rhettinger
rhettinger merged commit 438e9fc into python:master Sep 23, 2020
@rhettinger
rhettinger deleted the hypot_frac_order branch September 23, 2020 03:01
shihai1991 added a commit to shihai1991/cpython that referenced this pull request Sep 24, 2020
@shihai1991
Merge remote-tracking branch 'origin/master' into bpo_39337_new_3
e29ec44 
* origin/master: (27 commits)
  bpo-41428: Fix compiler warnings in unionobject.c (pythonGH-22388)
  bpo-41654: Fix compiler warning in MemoryError_dealloc() (pythonGH-22387)
  bpo-41833: threading.Thread now uses the target name (pythonGH-22357)
  bpo-30155: Add macros to get tzinfo from datetime instances (pythonGH-21633)
  bpo-33822: Update IDLE section of What's New 3.8 (pythonGH-22383)
  bpo-41844: Add IDLE section to What's New 3.9 (GN-22382)
  bpo-41841: Prepare IDLE News for 3.10 (pythonGH-22379)
  bpo-37779 : Add information about the overriding behavior of ConfigParser.read (pythonGH-15177)
  bpo-40170: Use inline _PyType_HasFeature() function (pythonGH-22375)
  bpo-40941: Fix stackdepth compiler warnings (pythonGH-22377)
  bpo-40941: Fix fold_tuple_on_constants() compiler warnings (pythonGH-22378)
  bpo-40521: Fix PyUnicode_InternInPlace() (pythonGH-22376)
  bpo-41834: Remove _Py_CheckRecursionLimit variable (pythonGH-22359)
  bpo-1635741, unicodedata: add ucd_type parameter to UCD_Check() macro (pythonGH-22328)
  bpo-1635741: Port _lsprof extension to multi-phase init (PEP 489) (pythonGH-22220)
  bpo-41513: Improve order of adding fractional values. Improve variable names. (pythonGH-22368)
  bpo-41816: `StrEnum.__str__` is `str.__str__` (pythonGH-22362)
  bpo-35764: Rewrite the IDLE Calltips doc section  (pythonGH-22363)
  bpo-41810: Reintroduce `types.EllipsisType`, `.NoneType` & `.NotImplementedType` (pythonGH-22336)
  bpo-41602: raise SIGINT exit code on KeyboardInterrupt from pymain_run_module (python#21956)
  ...
xzy3 pushed a commit to xzy3/cpython that referenced this pull request Oct 18, 2020
@rhettinger @xzy3-cdc
bpo-41513: Improve order of adding fractional values. Improve variabl…
4c15ba9 
…e names. (pythonGH-22368)
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@rhettinger @bedevere-bot @the-knights-who-say-ni
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