Change string representation of RealField

[videlec]

We change the string representation of RealField(XXX) from

Real Field with XX bits of precision

to

Real Floating-Point Field with XX bits of precision

The reason for this change is that "Real Field" is not precise enough. Beyond floating-point, "Real Field" could equivalently be used for fixed-point, intervals and balls. The standard terms in the literature are "floating-point arithmetic", "fixed-point arithmetic", "ball arithmetic" and "interval arithmetic", see eg

• ​https://en.wikipedia.org/wiki/Floating-point_arithmetic
• ​https://en.wikipedia.org/wiki/Interval_arithmetic
• ​https://hal.archives-ouvertes.fr/hal-00432152v3/

This ticket is part of a the refactorization #24457 that intends to clean computations involving the different kinds of real numbers.

The git branch was obtained by running the following command in $SAGE_ROOT/src

for file in $(grep -l "Real Field with" $(find . -name "*pyx" -o -name "*py" -o -name "*pxd" -o -name "*rst" -type f))
  do sed -i "s/Real Field with/Real Floating-Point Field with/g" $file
done

Tests work fine except for doctests that involves an output with a linebreak such as

sage: x = polygen(RR); r = (1 + x)/(1 - x^2); r.parent()
Fraction Field of Univariate Polynomial Ring in x over Real
Field with 53 bits of precision

(from src/sage/tests/french_book/polynomes.py line 218). These can also be handled using multiline sed replacement

for file in $(find . -name "*pyx" -o -name "*py" -o -name "*pxd" -o -name "*rst" -type f)
do
  sed -Ei '{N; s/Real(\s+)Field(\s+)with/Real\1Floating-Point Field\2with/; ty; P; D; :y}' $file
done

As part of this ticket, the printf percentage syntax has been changed to the newer Python 3 standard format syntax (see comment:22) in all real field representations.

---

Related discussion on sage-devel.

Component: basic arithmetic

Author: Vincent Delecroix, Ralf Stephan, Michael Jung

Branch/Commit: u/gh-mjungmath/24523 @ 7f7d902

Reviewer: Vincent Klein, Vincent Delecroix

Issue created by migration from https://trac.sagemath.org/ticket/24523

[videlec]

Dependencies: #24511

[rwst]

comment:3

I first changed find . to find src because I was in the sage top directory. Then I added g after / to replace multiple occurences of the pattern in one line. When applying the script there were several things that needed manual adaptation: in tests/french_book/nonlinear_doctest.py the print command of a doctest had to be changed to ensure aesthetic results. Also the script picks up conf.py files under src/doc and for some reasons git thinks it has to delete them and create them new, so I git checked out the originals of all src/doc/en/reference/*/conf.py files. The remaining doctest fails appear to be instances of split lines and, according to recent comments by Jeroen which I agree with, that if the output is one line the doctest output should be too, I joined those lines and replaced the pattern.

[rwst]

Branch: u/rws/24523

[rwst]

Commit: 137c4b8

[rwst]

comment:5

Also there was one doctest change in a pxd file. 127 files were changed.

---

New commits:

a782296	24511: Move create_RealField to real_field.py
977f62d	24511 deprecation
137c4b8	24523: Change string representation of RealField

[rwst]

Changed author from Vincent Delecroix to Vincent Delecroix, Ralf Stephan

[jdemeyer]

comment:6

Sorry to spoil the party, but what is wrong with "Real Field with XX bits of precision"? Doesn't the "XX bits of precision" imply already that it's floating point? I think that the shorter name Real Field is sufficient.

Note that also balls and intervals are floating-point, so do you plan to use Real Floating-point Interval Field and Real Floating-point Ball Field too?

[videlec]

comment:7

And anyway, this kind of things has to be agreed on on sage-devel.

[videlec]

comment:8

Replying to @jdemeyer:

Sorry to spoil the party, but what is wrong with "Real Field with XX bits of precision"?
Doesn't the "XX bits of precision" imply already that it's floating point? I think that the shorter name Real Field is sufficient.

Note that also balls and intervals are floating-point, so do you plan to use Real Floating-point Interval Field and Real Floating-point Ball Field too?

The rationale is: not precise enough. The "Real Field with XX bits of precision" could equivalently be used for intervals and balls. The standard terms in the literature are "floating-point arithmetic", "ball arithmetic" and "interval arithmetic".

[rwst]

comment:9

This already accumulates merge conflicts en masse.

[videlec]

comment:11

NOT to be merged: just testing what patchbots have to say...

---

New commits:

4ab32e2

24523: "Real Field" -> "Real Floating-point Field"

[videlec]

Changed commit from 137c4b8 to 4ab32e2

[videlec]

Changed branch from u/rws/24523 to u/vdelecroix/24523

[videlec]

Changed dependencies from #24511 to none

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

e3a54e6

24523: "Real Field" -> "Real Floating-point Field"

[dimpase]

comment:48

Do we have a followup for Complex Field? Because it has the same problem.

[dimpase]

comment:49

rebase please

[seblabbe]

It was asked on the sage-devel discussion whether people have an opinion.

Replying to [ticket:24523 ticket description]:

We change the string representation of RealField(XXX) from

Real Field with XX bits of precision

to

Real Floating-Point Field with XX bits of precision

+1 from me

[sagetrac-git]

Changed commit from e4a1d75 to 93cb1a2

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

1fa235c	Trac 24523: py3 format style + "Real Field" -> "Real Floating-Point Field"
93cb1a2	Trac #24523: change string repr "Real Field" -> "Real Floating-Point Field"

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

e654661	Trac 24523: "Real Field" -> "Real Floating-Point Field" + new formatting style
050aa3d	Trac #24523: change string repr "Real Field" -> "Real Floating-Point Field"

[sagetrac-git]

Changed commit from 93cb1a2 to 050aa3d

[sagetrac-git]

Changed commit from 050aa3d to 7f7d902

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

8c89c3f	Trac #24523: "Real Field" -> "Real Floating-Point Field" + new formatting style
7f7d902	Trac #24523: change string repr "Real Field" -> "Real Floating-Point Field"

[mjungmath]

comment:54

Replying to @dimpase:

Do we have a followup for Complex Field? Because it has the same problem.

Yes. See #24489.

Replying to @dimpase:

rebase please

Done.

[mjungmath]

comment:55

I wonder a bit about the changes in src/sage/tests/books/. Is that how it should be?

[seblabbe]

comment:56

Replying to @mjungmath:

I wonder a bit about the changes in src/sage/tests/books/. Is that how it should be?

Yes

[mkoeppe]

comment:57

rebase

[mkoeppe]

comment:58

Setting new milestone based on a cursory review of ticket status, priority, and last modification date.

[mkoeppe]

comment:59

Setting a new milestone for this ticket based on a cursory review.