Skip to content

ENH: Use Dragon4 algorithm to print floating values #9941

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 11 commits into from
Nov 5, 2017
Merged

ENH: Use Dragon4 algorithm to print floating values #9941

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
11 commits
Select commit Hold shift + click to select a range
28a9654
ENH: Port the Dragon4 implementation to C/Numpy
ahaldane Oct 28, 2017
aba0211
ENH: Implement float16 and float128 dragon4 output
ahaldane Nov 4, 2017
cbcff74
ENH: implement IEEE unbiased rounding in dragon4
ahaldane Oct 30, 2017
7c4e6ea
ENH: Add Dragon4 printing modes for "unique with cutoff"
ahaldane Nov 4, 2017
0b14f50
ENH: Add python interface to dragon4 algorithm
ahaldane Oct 28, 2017
05c27ef
ENH: Make numpy float scalars use dragon4 output
ahaldane Oct 28, 2017
0cf5cc0
ENH: Make arrayprint code use dragon4 algorithm
ahaldane Oct 29, 2017
39551ef
TST: update tests to account for dragon4 fixes
ahaldane Oct 29, 2017
170cf10
ENH: make dragon4 float format functions publicly visible
ahaldane Nov 4, 2017
9ab9e8b
TST: New tests for scalar/array reprs with dragon4
ahaldane Nov 4, 2017
a50f472
DOC: update documentation for dragon4
ahaldane Nov 4, 2017
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
24 changes: 24 additions & 0 deletions doc/release/1.14.0-notes.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -16,6 +16,8 @@ New functions

* ``parametrize``: decorator added to numpy.testing
* ``chebinterpolate``: Interpolate function at Chebyshev points.
* ``format_float_positional`` and ``format_float_scientific`` : format
floating-point scalars unambiguously with control of rounding and padding.


Deprecations
Expand Down Expand Up @@ -306,6 +308,28 @@ now supported for these arrays:
* `arr.resize(...)`
* `pickle.dumps(arr)`

Float printing now uses "dragon4" algorithm for shortest decimal representation
-------------------------------------------------------------------------------
All numpy floating-point types (16, 32, 64 and 128 bit) can now be printed to
give shortest decimal representation of the number, which uniquely identifies
the value from others of the same type.

New functions ``np.format_float_scientific`` and ``np.format_float_positional``
are provided to generate these decimal representations, with control over
rounding, trimming and padding.

The ``str`` and ``repr`` of floating-point scalars now shows the shortest
unique decimal representation. This means there will be a different number of
digits compared to numpy 1.13, for instance float64 and float128 will be longer
and float16 will be shorter.

For arrays of floating-point type, a new formatting option ``floatmode`` has
been added to ``np.set_printoptions`` and ``np.array2string``, which gives
control over uniqueness and rounding of printed elements in arrays. The new
default is ``floatmode='maxprec'`` with ``precision=8``, which will print at most
8 fractional digits, or fewer if an element can be uniquely represented with
fewer.


Changes
=======
Expand Down
2 changes: 2 additions & 0 deletions doc/source/reference/routines.io.rst
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -45,6 +45,8 @@ String formatting
array2string
array_repr
array_str
format_float_positional
format_float_scientific

Memory mapping files
--------------------
Expand Down
447 changes: 298 additions & 149 deletions numpy/core/arrayprint.py
View file
Open in desktop

Large diffs are not rendered by default.

2 changes: 2 additions & 0 deletions numpy/core/setup.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -728,6 +728,7 @@ def get_mathlib_info(*args):
join('src', 'multiarray', 'conversion_utils.h'),
join('src', 'multiarray', 'ctors.h'),
join('src', 'multiarray', 'descriptor.h'),
join('src', 'multiarray', 'dragon4.h'),
join('src', 'multiarray', 'getset.h'),
join('src', 'multiarray', 'hashdescr.h'),
join('src', 'multiarray', 'iterators.h'),
Expand Down Expand Up @@ -793,6 +794,7 @@ def get_mathlib_info(*args):
join('src', 'multiarray', 'datetime_busday.c'),
join('src', 'multiarray', 'datetime_busdaycal.c'),
join('src', 'multiarray', 'descriptor.c'),
join('src', 'multiarray', 'dragon4.c'),
join('src', 'multiarray', 'dtype_transfer.c'),
join('src', 'multiarray', 'einsum.c.src'),
join('src', 'multiarray', 'flagsobject.c'),
Expand Down
Loading