merge useasyforxmlgraphics

Author: mmatera

CHANGES.rst

@@ -89,9 +89,12 @@ Document updates
 Enhancements and Bug fixes:
 +++++++++++++++++++++++++++
 
-- Fix evaluation timeouts
+- Fix evaluation timeouts.
 - ``Sum``'s lower and upper bounds values can now be Mathics expressions
-
+- Partial fix for MathML 2D Graphics. Requires the installation of the package Asymptote, and to set
+  the variable ``Settings`UseAsyForGraphics2D`` to ``System`True``.
+- Set the numeric threshold in PossibleZeroQ  to 10^(-10), for compatibility with ``System`Chop``.
+- Catch possible exceptions generated by ``$UserName``.
 
 
 Miscelanea

mathics/builtin/arithmetic.py

@@ -1343,14 +1343,13 @@ class PossibleZeroQ(SympyFunction):
     def apply(self, expr, evaluation):
         "%(name)s[expr_]"
         from sympy.matrices.utilities import _iszero
-
         sympy_expr = expr.to_sympy()
         result = _iszero(sympy_expr)
         if result is None:
         # try expanding the expression
             exprexp = Expression("ExpandAll", expr).evaluate(evaluation)
             exprexp = exprexp.to_sympy()
-            result = _iszero(exprexp)        
+            result = _iszero(exprexp)
         if result is None:
             # Can't get exact answer, so try approximate equal
             numeric_val = Expression("N", expr).evaluate(evaluation)
@@ -1364,7 +1363,6 @@ def apply(self, expr, evaluation):
                     if Expression("Simplify", expr).evaluate(evaluation) == Integer(0)
                     else SymbolFalse
                 )
-
         return from_python(result)
 
 

mathics/builtin/graphics.py

@@ -3145,7 +3145,7 @@ def get_range(min, max):
 
         return elements, calc_dimensions
 
-    def boxes_to_tex(self, leaves=None, **options):
+    def boxes_to_tex(self, leaves=None, forxml=False, **options):
         if not leaves:
             leaves = self._leaves
         elements, calc_dimensions = self._prepare_elements(
@@ -3181,14 +3181,12 @@ def boxes_to_tex(self, leaves=None, **options):
             asy_background = ""
 
         tex = r"""
-\begin{asy}
 usepackage("amsmath");
 size(%scm, %scm);
 %s
 %s
 clip(%s);
 %s
-\end{asy}
 """ % (
             asy_number(width / 60),
             asy_number(height / 60),
@@ -3198,11 +3196,58 @@ def boxes_to_tex(self, leaves=None, **options):
             asy_completely_visible,
         )
 
-        return tex
+        if forxml:
+            return (tex, width, height)
+        else:
+            return "\n\\begin{asy}\n" + tex + "\n\\end{asy}\n"
 
     def boxes_to_xml(self, leaves=None, **options):
         if not leaves:
             leaves = self._leaves
+        evaluation = options.get("evaluation", None)
+        check_asy = False
+        if evaluation:
+            check_asy = evaluation.definitions.get_ownvalue("Settings`UseAsyForGraphics2D")
+            if check_asy:
+                check_asy = check_asy.replace.is_true()
+        if check_asy:
+            import os
+            from subprocess import DEVNULL, STDOUT, check_call
+            import tempfile
+            try:
+                check_call(['asy', '--version'], stdout=DEVNULL, stderr=DEVNULL)
+            except:
+                check_asy = False
+
+        if check_asy:
+            asy, width, height = self.boxes_to_tex(leaves, forxml=True, **options)
+            fin = os.path.join(tempfile._get_default_tempdir(), next(tempfile._get_candidate_names()))
+            fout = fin + ".svg"
+            with open(fin, 'w+') as borrador:
+                borrador.write(asy)
+
+            try:
+                check_call(['asy', '-f', 'svg', '--svgemulation' ,'-o', fout, fin], stdout=DEVNULL, stderr=DEVNULL)
+            except:
+                print("Asy failed to build a svg")
+                check_asy = False
+
+            if check_asy:
+                with open(fout, 'rt') as ff:
+                    svg = ff.read()
+
+                svg = svg[svg.find("<svg "):]
+                return (
+                    '<img  width="%dpx" height="%dpx" src="data:image/svg+xml;base64,%s"/>'
+                    % (
+                        int(width),
+                        int(height),
+                        base64.b64encode(svg.encode("utf8")).decode("utf8"),
+                    )
+                )
+        else:
+            print("Asy not available. Continue with standard")
+
         elements, calc_dimensions = self._prepare_elements(leaves, options, neg_y=True)
 
         xmin, xmax, ymin, ymax, w, h, width, height = calc_dimensions()

mathics/builtin/system.py

@@ -406,8 +406,16 @@ class UserName(Predefined):
 
     name = "$UserName"
 
+    messages = {
+        'nologin': "UserName not available in this system.",
+    }
+
     def evaluate(self, evaluation) -> String:
-        return String(os.getlogin())
+        try:
+            return String(os.getlogin())
+        except:
+            evaluation.message('$UserName', 'nologin')
+            return
 
 
 class Version(Predefined):

mathics/core/expression.py

@@ -2117,7 +2117,7 @@ def __neg__(self) -> 'Rational':
 
     @property
     def is_zero(self) -> bool:
-        return self.numerator().is_zero and not self.denominator().is_zero()
+        return self.numerator().is_zero and not(self.denominator().is_zero)
 
 
 class Real(Number):