Source Code for Module SloppyCell.ExprManip.Py2TeX

  1  from compiler.ast import * 
  2  import os 
  3   
  4  import AST 
  5   
  6  # This is just and istance of Mul to use when we group numerators and  
  7  #  denominators 
  8  _EMPTY_MUL = Mul((None, None)) 
  9   
 10 -def dict2TeX(d, name_dict, lhs_form='%s', split_terms=False, simpleTeX=False): 
 11      lines = [] 
 12      for lhs, rhs in d.items(): 
 13          if split_terms: 
 14              ast = AST.strip_parse(rhs) 
 15              pos, neg = [], [] 
 16              AST._collect_pos_neg(ast, pos, neg) 
 17              try: 
 18                  lhsTeX = lhs_form % expr2TeX(lhs, name_dict=name_dict) 
 19              except TypeError: 
 20                  lhsTeX = lhs_form 
 21              rhsTeX = _ast2TeX(pos[0], name_dict=name_dict) 
 22              lines.append(r'$ %s $ &=& $ %s $\\' % (lhsTeX, rhsTeX)) 
 23                            
 24              for term in pos[1:]: 
 25                  TeXed = _ast2TeX(term, name_dict=name_dict) 
 26                  lines.append(r' & & $ + \, %s $\\' % TeXed) 
 27              for term in neg: 
 28                  TeXed = _ast2TeX(term, name_dict=name_dict) 
 29                  lines.append(r' & & $ - \, %s $\\' % TeXed) 
 30          else: 
 31              lhsTeX = lhs_form % expr2TeX(lhs, name_dict=name_dict) 
 32              rhsTeX = expr2TeX(rhs, name_dict=name_dict) 
 33              lines.append(r'$ %s $ & = & $ %s $\\' % (lhsTeX, rhsTeX)) 
 34   
 35          if not simpleTeX: 
 36              # Force a space between TeX'd entries 
 37              lines[-1] = '%s[5mm]' % lines[-1] 
 38   
 39      all = os.linesep.join(lines) 
 40   
 41      if not simpleTeX: 
 42          all = all.replace(r'\frac{', r'\tabfrac{') 
 43          # This makes the fractions look much nicer in the tabular output. See 
 44          #  http://www.texnik.de/table/table.phtml#fractions 
 45          lines = [r'\providecommand{\tabfrac}[2]{%', 
 46                   r'   \setlength{\fboxrule}{0pt}%', 
 47                   r'   \fbox{$\frac{#1}{#2}$}}', 
 48                   r'\begin{longtable}{lll}'] + [all] + [r'\end{longtable}'] 
 49          all = os.linesep.join(lines) 
 50   
 51      return all 
 52   
 53 -def expr2TeX(expr, name_dict={}): 
 54      """ 
 55      Return a TeX version of a python math expression. 
 56   
 57      name_dict: A dictionary mapping variable names used in the expression to 
 58          preferred TeX expressions. 
 59      """ 
 60      ast = AST.strip_parse(expr) 
 61      return _ast2TeX(ast, name_dict=name_dict) 
 62   
 63 -def _ast2TeX(ast, outer=AST._FARTHEST_OUT, name_dict={},  
 64               adjust=0): 
 65      """ 
 66      Return a TeX version of an AST. 
 67   
 68      outer: The AST's 'parent' node, used to determine whether or not to  
 69          enclose the result in parentheses. The default of _FARTHEST_OUT will 
 70          never enclose the result in parentheses. 
 71   
 72      name_dict: A dictionary mapping variable names used in the expression to 
 73          preferred TeX expressions. 
 74   
 75      adjust: A numerical value to adjust the priority of this ast for 
 76          particular cases. For example, the denominator of a '/' needs  
 77          parentheses in more cases than does the numerator. 
 78      """ 
 79      if isinstance(ast, Name): 
 80          # Try to get a value from the name_dict, defaulting to ast.name if 
 81          #  ast.name isn't in name_dict 
 82          out = name_dict.get(ast.name, ast.name) 
 83      elif isinstance(ast, Const): 
 84          out = str(ast.value) 
 85      elif isinstance(ast, Add): 
 86          out = '%s + %s' % (_ast2TeX(ast.left, ast, name_dict), 
 87                             _ast2TeX(ast.right, ast, name_dict)) 
 88      elif isinstance(ast, Sub): 
 89          out = '%s - %s' % (_ast2TeX(ast.left, ast, name_dict), 
 90                             _ast2TeX(ast.right, ast, name_dict, adjust = 1)) 
 91      elif isinstance(ast, Mul) or isinstance(ast, Div): 
 92          # We collect all terms numerator and denominator 
 93          nums, denoms = [], [] 
 94          AST._collect_num_denom(ast, nums, denoms) 
 95          # _EMPTY_MUL ensures that parentheses are done properly, since every 
 96          #  element is now the child of a Mul 
 97          lam_func = lambda arg: _ast2TeX(arg, _EMPTY_MUL, name_dict) 
 98          nums = [lam_func(term) for term in nums] 
 99          if denoms: 
100              denoms = [lam_func(term) for term in denoms] 
101              out = r'\frac{%s}{%s}' % (r' \cdot '.join(nums), 
102                                        r' \cdot '.join(denoms)) 
103          else: 
104              out = r' \cdot '.join(nums) 
105      elif isinstance(ast, Power): 
106          out = '{%s}^{%s}' % (_ast2TeX(ast.left, ast, name_dict, adjust = 1), 
107                               _ast2TeX(ast.right, ast, name_dict)) 
108      elif isinstance(ast, UnarySub): 
109          out = '-%s' % _ast2TeX(ast.expr, ast, name_dict) 
110      elif isinstance(ast, UnaryAdd): 
111          out = '+%s' % _ast2TeX(ast.expr, ast, name_dict) 
112      elif isinstance(ast, CallFunc): 
113          lam_func = lambda arg: _ast2TeX(arg, name_dict=name_dict) 
114          name = lam_func(ast.node) 
115          args = [lam_func(arg) for arg in ast.args] 
116          if name == 'sqrt' and len(args) == 1: 
117              # Special case 
118              out = r'\sqrt{%s}' % args[0] 
119          else: 
120              out = r'\operatorname{%s}\left(%s\right)' % (name, r',\,'.join(args)) 
121      elif isinstance(ast, Or) or isinstance(ast, And): 
122          out = r'\operatorname{%s}' % (str(ast)) 
123           
124      if AST._need_parens(outer, ast, adjust): 
125          return out 
126      else: 
127          return r'\left(%s\right)' % out 
128