Description:

AlgebrawithSymPy 1.1.2

Algebraic Equations with SymPy
Introduction | Output Formatting
| Installation |
Try Live | Issues or Comments |
Change Log |
License
| GIT Repository
| PyPi Link
Website/Documentation (including API)
Introduction

This tool defines relations that all high school and college students would
recognize as mathematical equations.
They consist of a left hand side (lhs) and a right hand side (rhs) connected by
the relation operator "=". In addition, it sets some convenient defaults and
provides some controls of output formatting that may be useful even if
you do not use the Equation class (see Conveniences for
SymPy).
This tool applies operations to both sides of the equation simultaneously, just
as students are taught to do when
attempting to isolate (solve for) a variable. Thus the statement Equation/b
yields a new equation Equation.lhs/b = Equation.rhs/b
The intent is to allow using the mathematical tools in SymPy to rearrange
equations and perform algebra
in a stepwise fashion using as close to standard mathematical notation as
possible. In this way more people can successfully perform
algebraic rearrangements without stumbling
over missed details such as a negative sign.
A simple example as it would appear in a Jupyter
notebook is shown immediately below:

The last cell illustrates how it is possible to substitute numbers with
units into the solved equation to calculate a numerical solution with
proper units. The units(...) operation is part this package, not Sympy.
In IPython environments (IPython, Jupyter, Google Colab, etc...) there is
also a shorthand syntax for entering equations provided through the IPython
preparser. An equation can be specified as eq1 =@ a/b = c/d.

If no Python name is
specified for the equation (no eq_name to the left of =@), the equation
will still be defined, but will not be easily accessible for further
computation. The =@ symbol combination was chosen to avoid conflicts with
reserved python symbols while minimizing impacts on syntax highlighting
and autoformatting.
More examples of the capabilities of Algebra with Sympy are
here.
Many math packages such as SageMath
and Maxima have similar capabilities,
but require more knowledge of command syntax, plus they cannot easily be
installed in a generic python environment.
Convenience Tools and Defaults for Interactive Use of SymPy
Even if you do not use the Equation class, there are some convenience
tools and defaults that will probably make interactive use of SymPy in
Jupyter/IPython environments easier:

By default, all numbers in Sympy expressions without decimal points are
interpreted as integers (e.g. 2/3*x, where x is a sympy symbol, ->
2*x/3 not x*0.6666..., but if x is just a plain Python object then 2/3*x
-> x*0.66666...). This can be turned off with unset_integers_as_exact(),
which leads to standard Python behavior (2/3*x -> x*0.6666...) even for
Sympy expressions. Turn on with set_integers_as_exact(). When on the flag
algwsym_config.numerics.integers_as_exact = True.
Results of solve() are wrapped in FiniteSet() to force pretty-printing
of all of a solution set. See Controlling the Format of Interactive
Outputs.
It is possible to set the default display to show both the pretty-printed
result and the code version simultaneously. See Controlling the Format of Interactive
Outputs.

Controlling the Format of Interactive Outputs



These controls impact all Sympy objects and the Equation class.


In graphical environments (Jupyter) you will get rendered Latex such as
ab=cd or e−x2σ2. To also see the
code representation (what can be copied and pasted for
additional computation) set algwsym_config.output.show_code = True.
This will print the code version (e.g. Equation(a,b/c)) of equations
and sympy expression in addition to the human readable version. This code
version can be accessed directly by calling repr() on the
equation or expression.


In interactive text environments (IPython and command line) The human
readable string version of Sympy expressions are returned (for Equations a
= b rather than Equation(a,b)). This is equivalent to Calling print()
or str() on an expression.

To have the code version (can be copied and pasted as a
Python statement) returned, set algwsym_config.output.human_text = False.
Setting both algwsym_config.output.human_text = True
and algwsym_config.output.show_code = True, will return both the
code and human readable versions.



The equation label can be turned off by setting
algwsym_config.output.label = False.


Automatic wrapping of Equations as Latex equations can be activated
by setting algwsym_config.output.latex_as_equations to True. The
default is False. Setting this to True wraps output as LaTex equations,
wrapping them in \begin{equation}...\end{equation}. Equations formatted
this way will not be labeled with the internal name for the equation,
independent of the setting of algwsym_config.output.label.


By default solutions output by solve() are returned as a SymPy
FiniteSet() to force typesetting of the included solutions. To get Python
lists instead you can override this for the whole session by setting
algwsym_config.output.solve_to_list = True. For a one-off, simply
wrap the output of a solve in list() (e.g. list(solve(...))). One
advantage of list mode is that lists can be ordered. When
algwsym_config.output.solve_to_list = True solve() maintains the
solutions in the order the solve for variables were input.


Setup/Installation


Use pip to install in your python environment:
pip install -U Algebra-with-SymPy
To use in a running python session issue
the following command : from algebra_with_sympy import *.
This will also import the SymPy tools.
If you want to isolate this tool from the global namespace you are
working with change the import statement
to import algebra_with_sympy as spa, where
spa stands for "SymPy Algebra". Then all calls would be made to spa.funcname(). WARNING: Doing this makes shorthand equation input and
control of interactive output formats unavailable. To recover this
functionality the following code must be run in the interactive session.

Equation = spa.Equation
Eqn = Equation
algwsym_config = spa.algwsym_config

Try in binder


Issues or Comments


Issues and bug reports should be filed on
github.
Comments, questions, show and tell, etc. should go in the project
discussions.

Change Log


1.1.2 (August 13, 2024)

Test updates.
Verified compatibility with Sympy 1.13.2.


1.1.1 (July 25, 2024)

BUG FIX accommodate empty re.search results in preparser. Prevents
unnecessary error messages.


1.1.0 (July 22, 2024)

Setting integers as exact (set_integers_as_exact(), the default) now
only sets integers as exact within Sympy and Algebra_with_Sympy
expressions. This increases compatibility with other packages that
depend on integers being Python integers.
Refuse to import Algebra_with_Sympy if an incompatible
version of Sympy is installed in the environment.
Added warning explaining how to install a compatible version of Sympy.


1.0.2 (July 5, 2024)

Removed requirements for Jupyter and Jupyterlab as code will work in
vanilla python or Google Colab.
Workaround for Google Colab's inconsistent handling of mixed Latex and
plain text strings. This impacted display of equation labels in Colab.
BUG FIX: catch IPython not installed so that can run in plain vanilla
python.


1.0.1 (May 22, 2024)

BUG FIX: equation labels that include underscore characters "_" are now
accepted.
BUG FIX: wrapping equations formatted as LaTex equation (ie. surrounded
by \begin{equation}...\end{equation}) in the $..$ code used to
indicate markdown for MathJax was causing output errors in Quarto when
outputing to .tex or .pdf. This is now fixed without negatively
impacting MathJax rendering.
BUG FIX: Singleton results of solve unnecessarily wrapped by extra list
or finiteset. No longer double nested.
BUG FIX: When returning lists make solve respect user order of solutions.
BUG FIX: Equation output threw error when Algebra_with_Sympy was
imported as a submodule. Equation labeling turned off for this type of
import to avoid error.
BUG FIX: Equation labels are now copyable even with the newer MathJax
commonHTML rendering.
Updates to requirements.txt.
Documentation updates.


1.0.0 (January 2, 2024)

Added convenience operation units(...) which takes a string of space
separated symbols to use as units. This simply declares the symbols
to be positive, making them behave as units. This does not create units
that know about conversions, prefixes or systems of units. This lack
is on purpose to provide units that require the user to worry about
conversions (ideal in a teaching situation). To get units with built-in
conversions see sympy.physics.units.
Fixed issue #23 where cos() multiplied by a factor was not the same
type of object after simplify() acted on an expression. Required
embedding the Equation type in the sympy library. Until Equation is
incorporated into the primary Sympy repository a customized version of
the latest stable release will be used.
Fixed issue where trailing comments (ie. # a comment at the end of a
line) lead to input errors using compact =@ notation.
algwsym_config.output.latex_as_equations has a default value of False.
Setting this to True wraps output as LaTex equations wrapping them
in \begin{equation}...\end{equation}. Equations formatted this way
will not be labeled with the internal name for the equation.


0.12.0 (July 12, 2023)

Now defaults to interpreting numbers without decimal points as integers.
This can be turned off with unset_integers_as_exact() and on with
set_integers_as_exact(). When on the flag
algwsym_config.numerics.integers_as_exact = True.


0.11.0 (June 5, 2023)

Formatting of FiniteSets overridden so that the contents always
pretty-print. This removes the necessity of special flags to get
pretty output from solve.
Sympy solve() now works reliably with equations and outputs
pretty-printed solutions.
Added option algwsym_config.output.solve_to_list = True which causes
solve() to return solutions sets as Python lists. Using this option
prevents pretty-printing of the solutions produced by solve().
algwsym_config.output.show_code and
algwsym_config.output.human_text now work for all sympy objects, not
just Equation objects. This works
in terminal, IPython terminal and Jupyter. This is achieved by hooking
into the python display_hook and IPython display_formatter.
Added jupyter to requirements.txt so that virtual environment builds
will include jupyter.
The way __version__ was handled could break pip install. Changed to
generating the internal version during setup. This means the version
is now available as algwsym_version.


0.10.0 (Sep. 5, 2022)

Documentation updates and fixes.
Significantly increased test coverage (~98%).
Support for Eqn.rewrite(Add)
Solving (e.g. solve(Eqn,x)) now supported fully. Still experimental.
Bug fix: latex printing now supports custom printer.
Substitution into an Equation using Equations is now
supported (e.g. eq1.subs(eq2, eq3, ...)).
algebra_with_sympy.__version__ is now available for version checking
within python.
Bug fix: preparsing for =@ syntax no longer blocks obj? syntax for
getting docstrings in ipython.
More robust determination of equation names for labeling.


0.9.4 (Aug. 11, 2022)

Update to deal with new Sympy function piecewise_exclusive in v1.11.
Added user warning if a function does not extend for use with Equations
as expected. This also allows the package to be used even when a function
extension does fail.
Simplification of documentation preparation.
Typo fixes in preparser error messages.


0.9.3 (Aug. 9, 2022)

Added check for new enough version of IPython to use the preparser.
If IPython version too old, issue warning and do not accept =@ shorthand.


0.9.2 (Jun. 5, 2022)

=@ shorthand syntax for defining equations in IPython compatible
environments.
Fixed bug where root() override called sqrt() on bare expressions.


0.9.1 (Mar. 24, 2022)

Equations labeled with their python name, if they have one.
Added flags to adjust human readable output and equation labeling.
Accept equation as function argument in any position.
First pass at solve() accepting equations.
Added override of root() to avoid warning messages.
More unit tests.
First pass at documentation.


0.9.0 functionality equivalent to extension of SymPy in
PR#21333.

licensed under GNU V3 license

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
Copyright - Algebra with Sympy Contributors 2021, 2022, 2023, 2024

License

For personal and professional use. You cannot resell or redistribute these repositories in their original state.

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