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Merged
merged 2 commits into from
Sep 8, 2023
Merged

add int_valued function #25640

merged 2 commits into from
Sep 8, 2023

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smichr
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@smichr smichr commented Sep 6, 2023 •
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References to other Issues or PRs

Brief description of what is fixed or changed

This adds a function that indicates, regardless of precision, whether an expression is a Number with no decimal portion, e.g. Float(3) but not Float(3.1).

Done in anticipation of #25614 but useful whether that is committed or not.

Other comments

I am note sure what to do about int_valued(1e23) -> True; it is true that it has no remainder but it is also not what one might expect:

>>> Float(1e23)
1.00000000000000e+23
>>> int(_)
99999999999999991611392
>>> Float(1e23)._mpf_
(0, 2980232238769531, 25, 52)  # sign, mantissa, e for 2**e and bits in mantissa
>>> Float(1e23)._prec
53

>>> Float('1e23')._mpf_
(0, 11920928955078125, 23, 54)
>>> int(Float('1e23'))
100000000000000000000000

>>> Float(10**5)
100000.000000000
>>> int(_)
100000
>>> Float(10**5)._mpf_
(0, 3125, 5, 12)
>>> Float(10**5)._prec
53

How do I determine whether a number will suffer from precision loss or not? It seems that the only way to know is to store, at instantiation, a flag that indicates how the number was passed (string vs float, for example).

Release Notes

  • core
    • added int_valued function to sympy/core/numbers.py for testing whether an expression is a literal number with no decimal portion

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sympy-bot commented Sep 6, 2023 •
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Hi, I am the SymPy bot. I'm here to help you write a release notes entry. Please read the guide on how to write release notes.

Your release notes are in good order.

Here is what the release notes will look like:

  • core
    • added int_valued function to sympy/core/numbers.py for testing whether an expression is a literal number with no decimal portion (#25640 by @smichr)

This will be added to https://github.com/sympy/sympy/wiki/Release-Notes-for-1.13.

Click here to see the pull request description that was parsed. 
<!-- Your title above should be a short description of what
was changed. Do not include the issue number in the title. -->

#### References to other Issues or PRs
<!-- If this pull request fixes an issue, write "Fixes #NNNN" in that exact
format, e.g. "Fixes #1234" (see
https://tinyurl.com/auto-closing for more information). Also, please
write a comment on that issue linking back to this pull request once it is
open. -->


#### Brief description of what is fixed or changed

This adds a function that indicates, regardless of precision, whether an expression is a Number with no decimal portion, e.g. `Float(3)` but not `Float(3.1)`.

Done in anticipation of #25614 but useful whether that is committed or not.

#### Other comments

I am note sure what to do about `int_valued(1e23) -> True`; it is true that it has no remainder but it is also not what one might expect:
```python
>>> Float(1e23)
1.00000000000000e+23
>>> int(_)
99999999999999991611392
>>> Float(1e23)._mpf_
(0, 2980232238769531, 25, 52)  # sign, mantissa, e for 2**e and bits in mantissa
>>> Float(1e23)._prec
53

>>> Float('1e23')._mpf_
(0, 11920928955078125, 23, 54)
>>> int(Float('1e23'))
100000000000000000000000

>>> Float(10**5)
100000.000000000
>>> int(_)
100000
>>> Float(10**5)._mpf_
(0, 3125, 5, 12)
>>> Float(10**5)._prec
53
```

How do I determine whether a number will suffer from precision loss or not? It seems that the only way to know is to store, at instantiation, a flag that indicates how the number was passed (string vs float, for example).

#### Release Notes

<!-- Write the release notes for this release below between the BEGIN and END
statements. The basic format is a bulleted list with the name of the subpackage
and the release note for this PR. For example:

* solvers
  * Added a new solver for logarithmic equations.

* functions
  * Fixed a bug with log of integers. Formerly, `log(-x)` incorrectly gave `-log(x)`.

* physics.units
  * Corrected a semantical error in the conversion between volt and statvolt which
    reported the volt as being larger than the statvolt.

or if no release note(s) should be included use:

NO ENTRY

See https://github.com/sympy/sympy/wiki/Writing-Release-Notes for more
information on how to write release notes. The bot will check your release
notes automatically to see if they are formatted correctly. -->

<!-- BEGIN RELEASE NOTES -->
* core
    * added `int_valued` function to sympy/core/numbers.py for testing whether an expression is a literal number with no decimal portion
<!-- END RELEASE NOTES -->

Update

The release notes on the wiki have been updated.

@smichr smichr force-pushed the isint branch 2 times, most recently from 7a20c49 to 370e355 Compare September 7, 2023 04:39
oscarbenjamin
oscarbenjamin reviewed Sep 7, 2023
View reviewed changes
@smichr smichr force-pushed the isint branch 2 times, most recently from bbd7f94 to 60468c9 Compare September 8, 2023 01:21
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github-actions bot commented Sep 8, 2023

Benchmark results from GitHub Actions

Lower numbers are good, higher numbers are bad. A ratio less than 1
means a speed up and greater than 1 means a slowdown. Green lines
beginning with + are slowdowns (the PR is slower then master or
master is slower than the previous release). Red lines beginning
with - are speedups.

Significantly changed benchmark results (PR vs master)



Significantly changed benchmark results (master vs previous release)


| Change   | Before [8059df73] <sympy-1.12^0>   | After [c84dc53e]    |   Ratio | Benchmark (Parameter)                                                |
|----------|------------------------------------|---------------------|---------|----------------------------------------------------------------------|
| -        | 84.0±1ms                           | 55.0±0.4ms          |    0.65 | integrate.TimeIntegrationRisch02.time_doit(10)                       |
| -        | 84.7±1ms                           | 53.7±0.5ms          |    0.63 | integrate.TimeIntegrationRisch02.time_doit_risch(10)                 |
| +        | 20.0±0.1μs                         | 39.7±0.2μs          |    1.99 | integrate.TimeIntegrationRisch03.time_doit(1)                        |
| -        | 6.80±0.01ms                        | 3.67±0.01ms         |    0.54 | logic.LogicSuite.time_load_file                                      |
| -        | 2.10±0ms                           | 615±3μs             |    0.29 | polys.TimePREM_LinearDenseQuadraticGCD.time_op(3, 'sparse')          |
| -        | 10.4±0.03ms                        | 1.86±0.01ms         |    0.18 | polys.TimePREM_LinearDenseQuadraticGCD.time_op(5, 'sparse')          |
| -        | 361±2μs                            | 78.9±0.4μs          |    0.22 | polys.TimePREM_QuadraticNonMonicGCD.time_op(1, 'sparse')             |
| -        | 4.70±0.01ms                        | 345±0.7μs           |    0.07 | polys.TimePREM_QuadraticNonMonicGCD.time_op(3, 'sparse')             |
| -        | 10.5±0.02ms                        | 1.04±0ms            |    0.1  | polys.TimePREM_QuadraticNonMonicGCD.time_op(5, 'sparse')             |
| -        | 6.21±0.02ms                        | 3.82±0.01ms         |    0.61 | polys.TimeSUBRESULTANTS_LinearDenseQuadraticGCD.time_op(2, 'sparse') |
| -        | 27.5±0.03ms                        | 11.6±0.03ms         |    0.42 | polys.TimeSUBRESULTANTS_LinearDenseQuadraticGCD.time_op(3, 'sparse') |
| -        | 6.77±0.04ms                        | 1.13±0ms            |    0.17 | polys.TimeSUBRESULTANTS_QuadraticNonMonicGCD.time_op(1, 'sparse')    |
| -        | 15.8±0.06ms                        | 8.91±0.01ms         |    0.57 | polys.TimeSUBRESULTANTS_QuadraticNonMonicGCD.time_op(2, 'sparse')    |
| -        | 205±0.3ms                          | 68.4±0.07ms         |    0.33 | polys.TimeSUBRESULTANTS_QuadraticNonMonicGCD.time_op(3, 'sparse')    |
| -        | 6.36±0.02ms                        | 504±2μs             |    0.08 | polys.TimeSUBRESULTANTS_SparseGCDHighDegree.time_op(3, 'sparse')     |
| -        | 27.3±0.08ms                        | 803±2μs             |    0.03 | polys.TimeSUBRESULTANTS_SparseGCDHighDegree.time_op(5, 'sparse')     |
| -        | 591±1μs                            | 201±0.9μs           |    0.34 | polys.TimeSUBRESULTANTS_SparseNonMonicQuadratic.time_op(1, 'sparse') |
| -        | 6.32±0.02ms                        | 205±0.7μs           |    0.03 | polys.TimeSUBRESULTANTS_SparseNonMonicQuadratic.time_op(3, 'sparse') |
| -        | 16.4±0.02ms                        | 207±0.6μs           |    0.01 | polys.TimeSUBRESULTANTS_SparseNonMonicQuadratic.time_op(5, 'sparse') |
| -        | 162±0.5μs                          | 90.5±0.2μs          |    0.56 | solve.TimeMatrixOperations.time_rref(3, 0)                           |
| -        | 306±0.5μs                          | 106±0.3μs           |    0.35 | solve.TimeMatrixOperations.time_rref(4, 0)                           |
| -        | 29.9±0.03ms                        | 12.7±0.04ms         |    0.43 | solve.TimeSolveLinSys189x49.time_solve_lin_sys                       |



Full benchmark results can be found as artifacts in GitHub Actions

(click on checks at the top of the PR).

      		
    

  





        


            

            
            

              
            

        

      


      

            
  
  

    
  
    
    

  

  

  


    












      

  
            

    

      
    

    


      


          @smichr
smichr




        changed the title
add is_int property

add int_valued function


      Sep 8, 2023

    

  



    







      

  
      



  

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        @oscarbenjamin
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        merged commit e6c67c4
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    Sep 8, 2023

  







  

  
  

  
      @smichr
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    deleted the
    
      
        isint
    
    branch

    September 11, 2023 23:03    
    













  
  

    

      

  




      


    


    

      

        
      

  
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