(Prueba) Probando parse_latex o como pasar expresiones LaTeX a SymPy

Importamos la función parse_latex:



In [11]:

    
from sympy.parsing.latex import parse_latex

Solo nos queda pasar un string con la expresión LaTeX para que la función devuelva la expresión en código entendible por Sympy. NOTA: El string conviene pasarlo en formato "raw string literal"

Uso:



In [12]:

    
parse_latex(r'\frac{x^2}{\sqrt{y}}')









    Out[12]:





x**2/sqrt(y)

Ejemplos



In [13]:

    
import numpy as np
import pandas as pd

Creando un array numpy elemento a elemento



In [14]:

    
x = np.empty([3], dtype=object)
x









    Out[14]:





array([None, None, None], dtype=object)



In [15]:

    
x[0]=parse_latex(r'\frac{x^2}{\sqrt{y}}')
x









    Out[15]:





array([x**2/sqrt(y), None, None], dtype=object)

Creando el array directamente



In [16]:

    
y = list(np.array([parse_latex(r'x+y=6'),parse_latex(r'x-y=0')]))
y









    Out[16]:





[Eq(x + y, 6), Eq(x - y, 0)]



In [17]:

    
from sympy import solve, latex

latex(solve(list(y)))









    Out[17]:





'\\left \\{ x : 3, \\quad y : 3\\right \\}'

Con un dataframe



In [18]:

    
z = pd.DataFrame(np.array([parse_latex(r'x+y=6'),parse_latex(r'x-y=0')]))
z









    Out[18]:







  
    
      
      0
    
  
  
    
      0
      Eq(x + y, 6)
    
    
      1
      Eq(x - y, 0)



In [19]:

    
z.columns









    Out[19]:





RangeIndex(start=0, stop=1, step=1)



In [20]:

    
for i in z.index:
    print(z.loc[i][0])









    



Eq(x + y, 6)
Eq(x - y, 0)



In [21]:

    
latex(solve(z.loc[i][0] for i in z.index))









    Out[21]:





'\\left \\{ x : 3, \\quad y : 3\\right \\}'



In [22]:

    
for i in z.index: print(z.loc[i][0])









    



Eq(x + y, 6)
Eq(x - y, 0)

Más de un sistema en el dataframe



In [23]:

    
v = pd.DataFrame(np.array([[parse_latex(r'x+y=6'),parse_latex(r'x-y=0')]]))
v









    Out[23]:







  
    
      
      0
      1
    
  
  
    
      0
      Eq(x + y, 6)
      Eq(x - y, 0)



In [24]:

    
for i in v.index:
    print(list(v.iloc[i][:]))
    print(solve(list(v.loc[i][:])))









    



[Eq(x + y, 6), Eq(x - y, 0)]
{x: 3, y: 3}



In [ ]:

Dataframe en latex



In [25]:

    
z = pd.DataFrame(np.array([['x+y=6','x-y=0']]))
z



In [26]:

    
z.apply(parse_latex)









    



---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-26-057c6ed86b75> in <module>()
----> 1 z.apply(parse_latex)

~/Mis_aplicaciones/anaconda3/lib/python3.6/site-packages/pandas/core/frame.py in apply(self, func, axis, broadcast, raw, reduce, result_type, args, **kwds)
   6012                          args=args,
   6013                          kwds=kwds)
-> 6014         return op.get_result()
   6015 
   6016     def applymap(self, func):

~/Mis_aplicaciones/anaconda3/lib/python3.6/site-packages/pandas/core/apply.py in get_result(self)
    316                                       *self.args, **self.kwds)
    317 
--> 318         return super(FrameRowApply, self).get_result()
    319 
    320     def apply_broadcast(self):

~/Mis_aplicaciones/anaconda3/lib/python3.6/site-packages/pandas/core/apply.py in get_result(self)
    140             return self.apply_raw()
    141 
--> 142         return self.apply_standard()
    143 
    144     def apply_empty_result(self):

~/Mis_aplicaciones/anaconda3/lib/python3.6/site-packages/pandas/core/apply.py in apply_standard(self)
    246 
    247         # compute the result using the series generator
--> 248         self.apply_series_generator()
    249 
    250         # wrap results

~/Mis_aplicaciones/anaconda3/lib/python3.6/site-packages/pandas/core/apply.py in apply_series_generator(self)
    275             try:
    276                 for i, v in enumerate(series_gen):
--> 277                     results[i] = self.f(v)
    278                     keys.append(v.name)
    279             except Exception as e:

~/Mis_aplicaciones/anaconda3/lib/python3.6/site-packages/sympy/parsing/latex/__init__.py in parse_latex(s)
     29 
     30     if _latex is not None:
---> 31         return _latex.parse_latex(s)

~/Mis_aplicaciones/anaconda3/lib/python3.6/site-packages/sympy/parsing/latex/_parse_latex_antlr.py in parse_latex(sympy)
     71     matherror = MathErrorListener(sympy)
     72 
---> 73     stream = antlr4.InputStream(sympy)
     74     lex = LaTeXLexer(stream)
     75     lex.removeErrorListeners()

~/Mis_aplicaciones/anaconda3/lib/python3.6/site-packages/antlr4/InputStream.py in __init__(self, data)
     18         self.name = "<empty>"
     19         self.strdata = data
---> 20         self._loadString()
     21 
     22     def _loadString(self):

~/Mis_aplicaciones/anaconda3/lib/python3.6/site-packages/antlr4/InputStream.py in _loadString(self)
     22     def _loadString(self):
     23         self._index = 0
---> 24         self.data = [ord(c) for c in self.strdata]
     25         self._size = len(self.data)
     26 

~/Mis_aplicaciones/anaconda3/lib/python3.6/site-packages/antlr4/InputStream.py in <listcomp>(.0)
     22     def _loadString(self):
     23         self._index = 0
---> 24         self.data = [ord(c) for c in self.strdata]
     25         self._size = len(self.data)
     26 

TypeError: ('ord() expected a character, but string of length 5 found', 'occurred at index 0')



In [ ]:

    
#Código para exportar el notebook a markdown (Opcional)
!jupyter nbconvert --to=markdown Probando_parse_latex.ipynb