Update app.py

app.py

@@ -57,25 +57,25 @@ def clean_latex2(latex):
     latex = re.sub(r'\\[ \t\n\r\f\v]*', '', latex)
     latex = re.sub(r'\\([+\-=])', r'\1', latex)
 
-    # Remove common misreads like \text{...}, \mathbf{...}, \nabla
+    # Remove garbage LaTeX elements
     latex = re.sub(r'\\text\s*\{.*?\}', '', latex)
     latex = re.sub(r'\\mathbf\s*\{.*?\}', '', latex)
-    latex = latex.replace('\\nabla', '')
-    latex = latex.replace('nabla', '')
-    latex = latex.replace('\\cdot', '*')
+    latex = re.sub(r'\\mathrm\s*\{.*?\}', '', latex)
+    latex = re.sub(r'\\[a-zA-Z]+\s*', '', latex)  # kill things like \mathbf, \times, \cdot, \nabla
+
+    latex = latex.replace('{', '').replace('}', '')
     latex = latex.replace('−', '-').replace('–', '-')
 
     replacements = {
-        r'\\chi': 'x', r'\\xi': 'x',
-        r'\\gamma': 'y', r'\\beta': 'b',
-        r'\\alpha': 'x', r'\\vartheta': '3',
-        r'mathcal': '', r'mathrm': '',
+        'chi': 'x', 'xi': 'x', 'alpha': 'x',
+        'beta': 'b', 'gamma': 'y', 'vartheta': '3',
+        'mathcal': '', 'cal': '', 'mathrm': ''
     }
     for wrong, right in replacements.items():
         latex = re.sub(wrong, right, latex)
 
-    # Remove curly braces
-    latex = latex.replace('{', '').replace('}', '')
+    # Remove remaining junk
+    latex = re.sub(r'[^0-9a-zA-Z=+\-*/().,\n ]', '', latex)
     latex = latex.strip().rstrip(',')
 
     return latex