Feat: change frac to dfrac for fractions

mapytex/calculus/API/expression.py

@@ -74,10 +74,10 @@ class Expression(object):
         2 + 3 \\times 4
         >>> e = Expression.from_str("2+3/4")
         >>> print(e)
-        2 + \\frac{3}{4}
+        2 + \\dfrac{3}{4}
         >>> es = e.simplify()
         >>> print(es)
-        \\frac{11}{4}
+        \\dfrac{11}{4}
         >>> Expression.set_render('txt')
         """
         from .tokens.token import Token

mapytex/calculus/core/MO/fraction.py

@@ -35,7 +35,7 @@ class MOFraction(Molecule):
         >>> print(f.__txt__)
         2 / 3
         >>> print(f.__tex__)
-        \\frac{2}{3}
+        \\dfrac{2}{3}
         >>> print(f)
         2 / 3
         >>> f = MOFraction(2, 3, negative = True)

mapytex/calculus/core/renders/tree2tex.py

@@ -117,17 +117,17 @@ def div2tex(left, right):
 
     >>> from ..MO import MO
     >>> div2tex(MO.factory(2), MO.factory(3))
-    '\\frac{2}{3}'
+    '\\dfrac{2}{3}'
     >>> from ..tree import Tree
     >>> t = Tree.from_str("1/2")
     >>> div2tex(t, MO.factory(3))
-    '\\frac{\\frac{1}{2}}{3}'
+    '\\dfrac{\\dfrac{1}{2}}{3}'
     >>> t = Tree.from_str("1+2")
     >>> div2tex(t, MO.factory(3))
-    '\\frac{1 + 2}{3}'
+    '\\dfrac{1 + 2}{3}'
     >>> t = Tree.from_str("1*2")
     >>> div2tex(MO.factory(3), t)
-    '\\frac{3}{1 \\times 2}'
+    '\\dfrac{3}{1 \\times 2}'
     """
     try:
         left_ = tree2tex(left)
@@ -138,7 +138,7 @@ def div2tex(left, right):
     except (AttributeError, ValueError):
         right_ = right.__tex__
 
-    return "\\frac{" + left_ + "}{" + right_ + "}"
+    return "\\dfrac{" + left_ + "}{" + right_ + "}"
 
 
 def pow2tex(left, right):