Changeset 7231:9a53ba484dcb

Timestamp:

10/29/07 13:44:57 (6 years ago)

Author:

Joel B. Mohler <jbm5@…>

Branch:

default

Children:

7232:e054455cbf30, 7233:6c1e61faebf2

Message:

Monoids, algebras, power series, polynomials and symbolic rings all latex variable names *much* better now

Location:

sage

Files:

• algebras/free_algebra_element.py (modified) (1 diff)
• calculus/calculus.py (modified) (2 diffs)
• misc/latex.py (modified) (2 diffs)
• misc/preparser.py (modified) (1 diff)
• monoids/free_monoid_element.py (modified) (3 diffs)
• rings/laurent_series_ring_element.pyx (modified) (3 diffs)
• rings/polynomial/multi_polynomial_ring_generic.pyx (modified) (5 diffs)
• rings/polynomial/polynomial_element.pyx (modified) (1 diff)
• rings/polynomial/polynomial_ring.py (modified) (1 diff)
• rings/power_series_ring.py (modified) (2 diffs)
• rings/power_series_ring_element.pyx (modified) (2 diffs)
• structure/parent_gens.pyx (modified) (3 diffs)

sage/algebras/free_algebra_element.py

@@ -86 +86 @@
             sage: latex(-x+3*y^20*z)
             \left(-1\right)x + 3y^{20}z
+            sage: alpha,beta,gamma=FreeAlgebra(ZZ,3,'alpha,beta,gamma').gens()
+            sage: latex(alpha-beta)
+            \alpha + \left(-1\right)\beta
         """
         v = self.__monomial_coefficients.items()

sage/calculus/calculus.py

@@ -225 +225 @@
 
 import operator
-from sage.misc.latex import latex, latex_varify
+from sage.misc.latex import latex, latex_variable_name
 from sage.structure.sage_object import SageObject
 
@@ -3290 +3290 @@
         except AttributeError:
             pass
-        a = self._name
-        if len(a) > 1:
-            m = re.search('(\d|[.,])+$',a)
-            if m is None:
-                a = latex_varify(a)
-            else:
-                b = a[:m.start()]
-                a = '%s_{%s}'%(latex_varify(b), a[m.start():])
-                
-        self.__latex = a
-        return a
+        self.__latex = latex_variable_name(self._name)
+        return self.__latex
 
     def _maxima_init_(self):

sage/misc/latex.py

@@ -604 +604 @@
                    'omega',
                    'Omega']
-                   
 
 def latex_varify(a):
@@ -613 +612 @@
     else:
         return '\\mbox{%s}'%a
-    
+
 def latex_variable_name(x):
     """
     Return latex version of a variable name.
-    
-    The rule is this:
-        x393 --> x_{393}   
-    I.e., always replace the last numeric part by _{number}.
-    """
-    import re
-    # * The "\d" means "decimal digit"
-    # * The "+" means "1 or more"
-    # * The "$" means "at the end of the line"
-    m = re.search('\d+$',x)
-    if m is None:
-        return x
-    return '%s_{%s}'%(latex_varify(x[:m.start()]), x[m.start():])
+
+    Here are some guiding principles for usage of this function:
+    1)  If the variable is a single letter, that is the latex version.
+    2)  If the variable name is suffixed by a number, we put the number in the subscript.
+    3)  If the variable name contains an '_' we start the subscript at the underscore.
+        Note that #3 trumps rule #2.
+    4)  If a component of the variable is a greek letter, escape it properly.
+    5)  Recurse nicely with subscripts.
+
+    Refer to the examples section for how these rules might play out in practice.
+
+    EXAMPLES:
+        sage: import sage.misc.latex as latex_module
+        sage: latex_variable_name = latex_module.latex_variable_name
+        sage: latex_variable_name('a')
+        'a'
+        sage: latex_variable_name('abc')
+        '\\mbox{abc}'
+        sage: latex_variable_name('sigma')
+        '\\sigma'
+        sage: latex_variable_name('sigma_k')
+        '\\sigma_{k}'
+        sage: latex_variable_name('sigma389')
+        '\\sigma_{389}'
+        sage: latex_variable_name('beta_00')
+        '\\beta_{00}'
+        sage: latex_variable_name('Omega84')
+        '\\Omega_{84}'
+        sage: latex_variable_name('sigma_alpha')
+        '\\sigma_{\\alpha}'
+        sage: latex_variable_name('nothing1')
+        '\\mbox{nothing}_{1}'
+        sage: latex_variable_name('nothing_abc')
+        '\\mbox{nothing}_{\\mbox{abc}}'
+        sage: latex_variable_name('alpha_beta_gamma12')
+        '\\alpha_{\\beta_{\\gamma_{12}}}'
+
+    AUTHORS:
+        -- Joel B. Mohler -- drastic rewrite and many doc-tests
+    """
+    underscore = x.find("_")
+    if underscore == -1:
+        import re
+        # * The "\d|[.,]" means "decimal digit" or period or comma
+        # * The "+" means "1 or more"
+        # * The "$" means "at the end of the line"
+        m = re.search('(\d|[.,])+$',x)
+        if m is None:
+            prefix = x
+            suffix = None
+        else:
+            prefix = x[:m.start()]
+            suffix = x[m.start():]
+    else:
+        prefix = x[:underscore]
+        suffix = x[underscore+1:]
+    if suffix and len(suffix) > 0:
+        # handle the suffix specially because it very well might be numeric
+        # I use strip to avoid using regex's -- It makes it a bit faster (and the code is more comprehensible to non-regex'ed people)
+        if suffix.strip("1234567890")!="":
+            suffix = latex_variable_name(suffix) # recurse to deal with recursive subscripts
+        return '%s_{%s}'%(latex_varify(prefix), suffix)
+    else:
+        return latex_varify(prefix)

sage/misc/preparser.py

@@ -475 +475 @@
             gen_list = [s.strip() for s in line[i+2:gen_end].split(',')]
             for g in gen_list:
-                if not g.isalnum() or len(g) == 0 or not g[0].isalpha():
+                if (not g.isalnum() and not g.replace("_","").isalnum()) or len(g) == 0 or not g[0].isalpha():
                     raise SyntaxError, "variable name (='%s') must be alpha-numeric and begin with a letter"%g
 

sage/monoids/free_monoid_element.py

@@ -26 +26 @@
 from sage.rings.integer import Integer
 from sage.structure.element import MonoidElement
-from sage.misc.latex import latex, latex_varify
+from sage.misc.latex import latex, latex_variable_name
 
 def is_FreeMonoidElement(x):
@@ -121 +121 @@
             sage: z = F([(0,5),(1,2),(0,10),(0,2),(1,2)])
             sage: z._latex_()
-            '\\mbox{a0}^{5}\\mbox{a1}^{2}\\mbox{a0}^{12}\\mbox{a1}^{2}'
+            'a_{0}^{5}a_{1}^{2}a_{0}^{12}a_{1}^{2}'
             sage: F, (alpha,beta,gamma) = FreeMonoid(3, 'alpha,beta,gamma').objgens()
             sage: latex(alpha*beta*gamma)
@@ -128 +128 @@
         s = ""
         v = self._element_list
-        x = self.parent().variable_names()
+        x = self.parent().latex_variable_names()
         for i in range(len(v)):
             g = x[int(v[i][0])]
             e = v[i][1]
             if e == 1:
-                s += "%s"%(latex_varify(g),)
-            else:
-                s += "%s^{%s}"%(latex_varify(g),e)
+                s += "%s"%(g,)
+            else:
+                s += "%s^{%s}"%(g,e)
         if len(s) == 0: s = "1"
         return s

sage/rings/laurent_series_ring_element.pyx

@@ -234 +234 @@
             sage: f = (17/2)*x^-2 + x + x^2 + 3*x^4 + O(x^7)
             sage: latex(f)
-            \frac{\frac{17}{2}}{x^{2}} + x + x^{2} + 3x^{4} + O(\text{x}^{7})
+            \frac{\frac{17}{2}}{x^{2}} + x + x^{2} + 3x^{4} + O(x^{7})
         """
         if self.is_zero():
@@ -245 +245 @@
         valuation = self.__n
         m = len(v)
-        X = self._parent.variable_name()
+        X = self._parent.latex_variable_names()[0]
         atomic_repr = self._parent.base_ring().is_atomic_repr()
         first = True
@@ -280 +280 @@
                 bigoh = "O(1)"
             elif pr == 1:
-                bigoh = "O(%s)"%sage.misc.latex.latex(self._parent.variable_name())
+                bigoh = "O(%s)"%(X,)
             else:
-                bigoh = "O(%s^{%s})"%(sage.misc.latex.latex(self._parent.variable_name()),pr)
+                bigoh = "O(%s^{%s})"%(X,pr)
             if s == " ":
                 return bigoh

sage/rings/polynomial/multi_polynomial_ring_generic.pyx

@@ -7 +7 @@
 from sage.rings.integer_ring import ZZ
 from sage.rings.polynomial.polydict import PolyDict
+from sage.misc.latex import latex_variable_name
 import multi_polynomial_element
 import polynomial_ring
@@ -208 +209 @@
 
     def _latex_(self):
-        vars = str(self.latex_variable_names()).replace('\n','').replace("'",'')
-        return "%s[%s]"%(sage.misc.latex.latex(self.base_ring()), vars[1:-1])
-
+        vars = ', '.join(self.latex_variable_names())
+        return "%s[%s]"%(sage.misc.latex.latex(self.base_ring()), vars)
 
     def _ideal_class_(self):
@@ -382 +382 @@
         raise NotImplementedError
 
-    def latex_variable_names(self):
-        """
-        Returns the list of variable names suitable for latex output.
-
-        All '_SOMETHING' substrings are replaced by '_{SOMETHING}' recursively
-        so that subscripts of subscripts work.
-
-        EXAMPLES:
-            sage: R, x = PolynomialRing(QQ,'x',12).objgens()
-            sage: x
-            (x0, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11)
-            sage: print R.latex_variable_names ()
-            ['x_{0}', 'x_{1}', 'x_{2}', 'x_{3}', 'x_{4}', 'x_{5}', 'x_{6}', 'x_{7}', 'x_{8}', 'x_{9}', 'x_{10}', 'x_{11}']
-            sage: f = x[0]^3 + 15/3 * x[1]^10
-            sage: print latex(f)
-            5 x_{1}^{10} + x_{0}^{3}
-        """
-        if self._latex_names is not None:
-            return self._latex_names
-        names = []
-        for g in self.variable_names():
-            i = len(g)-1
-            while i >= 0 and g[i].isdigit():
-                i -= 1
-            if i < len(g)-1:
-                g = '%s_{%s}'%(g[:i+1], g[i+1:])
-            names.append(g)
-        self._latex_names = names
-        return names
-
     def __reduce__(self):
         """
@@ -420 +390 @@
         names = self.variable_names()
         order = self.term_order()
-        
+
         return unpickle_MPolynomialRing_generic_v1,(base_ring, n, names, order)
 
@@ -427 +397 @@
         r"""
         Return a random polynomial in this polynomial ring.
-        
+
         INPUT:
             degree -- maximum total degree of resulting polynomial

sage/rings/polynomial/polynomial_element.pyx

@@ -888 +888 @@
         r = reversed(xrange(m))
         if name is None:
-            name = self.parent().variable_name()
+            name = self.parent().latex_variable_names()[0]
         atomic_repr = self.parent().base_ring().is_atomic_repr()
         for n in reversed(xrange(m)):

sage/rings/polynomial/polynomial_ring.py

@@ -378 +378 @@
 
     def _latex_(self):
-        return "%s[%s]"%(latex.latex(self.base_ring()), latex.latex(self.variable_name()))
-        
+        """
+        EXAMPLES:
+            sage: S.<alpha12>=ZZ[]
+            sage: latex(S)
+            \mathbf{Z}[\alpha_{12}]
+        """
+        return "%s[%s]"%(latex.latex(self.base_ring()), self.latex_variable_names()[0])
+
     def __set_polynomial_class(self, cls=None):
         from sage.rings.padics.padic_ring_capped_relative import pAdicRingCappedRelative

sage/rings/power_series_ring.py

@@ -59 +59 @@
     sage: R.<t> = PowerSeriesRing(QQ, sparse=True)
     sage: latex(-2/3*(1/t^3) + 1/t + 3/5*t^2 + O(t^5))
-    \frac{-\frac{2}{3}}{t^{3}} + \frac{1}{t} + \frac{3}{5}t^{2} + O(\text{t}^{5})
+    \frac{-\frac{2}{3}}{t^{3}} + \frac{1}{t} + \frac{3}{5}t^{2} + O(t^{5})
     sage: S = parent(1/t); S
     Sparse Laurent Series Ring in t over Rational Field    
@@ -279 +279 @@
             sage: latex(R)
             \mathbf{F}_{17}[[y]]
-        """
-        return "%s[[%s]]"%(latex.latex(self.base_ring()), self.variable_name())
+            sage: R = GF(17)[['y12']]
+            sage: latex(R)
+            \mathbf{F}_{17}[[y_{12}]]
+        """
+        return "%s[[%s]]"%(latex.latex(self.base_ring()), self.latex_variable_names()[0])
 
     def __call__(self, f, prec=infinity, check=True):

sage/rings/power_series_ring_element.pyx

@@ -473 +473 @@
         v = self.list()
         m = len(v)
-        X = self._parent.variable_name()
+        X = self._parent.latex_variable_names()[0]
         atomic_repr = self._parent.base_ring().is_atomic_repr()
         first = True
@@ -504 +504 @@
                 bigoh = "O(1)"
             elif self._prec == 1:
-                bigoh = "O(%s)"%sage.misc.latex.latex(self._parent.gen())
+                bigoh = "O(%s)"%(X,)
             else:
-                bigoh = "O(%s^{%s})"%(sage.misc.latex.latex(self._parent.gen()),self._prec)
+                bigoh = "O(%s^{%s})"%(X,self._prec)
             if s == " ":
                 return bigoh

sage/structure/parent_gens.pyx

@@ -58 +58 @@
 
 import sage.misc.defaults
-import sage.misc.latex
+from sage.misc.latex import latex_variable_name
 import gens_py
 import parent
@@ -121 +121 @@
         if len(N) == 0:
             raise ValueError, "variable name must be nonempty"
-        if not N.isalnum():
+        if not N.isalnum() and not N.replace("_","").isalnum():
+            # We must be alphanumeric, but we make an exception for non-leading '_' characters.
             raise ValueError, "variable names must be alphanumeric, but one is '%s' which is not."%N
         if not N[0].isalpha():
@@ -377 +378 @@
 
     def latex_variable_names(self):
+        """
+        Returns the list of variable names suitable for latex output.
+
+        All '_SOMETHING' substrings are replaced by '_{SOMETHING}' recursively
+        so that subscripts of subscripts work.
+
+        EXAMPLES:
+            sage: R, x = PolynomialRing(QQ,'x',12).objgens()
+            sage: x
+            (x0, x1, x2, x3, x4, x5, x6, x7, x8, x9, x10, x11)
+            sage: print R.latex_variable_names ()
+            ['x_{0}', 'x_{1}', 'x_{2}', 'x_{3}', 'x_{4}', 'x_{5}', 'x_{6}', 'x_{7}', 'x_{8}', 'x_{9}', 'x_{10}', 'x_{11}']
+            sage: f = x[0]^3 + 15/3 * x[1]^10
+            sage: print latex(f)
+            5 x_{1}^{10} + x_{0}^{3}
+        """
         if self._latex_names != None:
             return self._latex_names
         # Compute the latex versions of the variable names.
-        self._latex_names = []
-        for x in self.variable_names():
-            self._latex.append(sage.misc.latex.latex_variable_name(x))
+        self._latex_names = [latex_variable_name(x) for x in self.variable_names()]
         return self._latex_names