Update app.py

app.py

@@ -15,15 +15,14 @@ model = LatexOCR()
 
 # Clean LaTeX output
 def clean_latex(latex):
-    # 🔧 Remove bad spacing escapes and redundant slashes
     latex = latex.replace('\\ ', '')
     latex = latex.replace('\\\\', '\\')
     latex = re.sub(r'\\[ \t\n\r\f\v]*', '', latex)
 
-    # ✅ Fix invalid LaTeX escapes like \+ \- \=
+    # Fix invalid LaTeX escapes like \+ \- \=
     latex = re.sub(r'\\([+\-=])', r'\1', latex)
 
-    # 🔁 Replace common misrecognized symbols
+    # Replace common misrecognized symbols
     replacements = {
         r'\\chi': 'x', r'chi': 'x',
         r'\\xi': 'x', r'xi': 'x',
@@ -32,42 +31,32 @@ def clean_latex(latex):
         r'\\gamma': 'y', r'gamma': 'y',
         r'\\vartheta': '3', r'vartheta': '3',
         r'\\mathcalW': 'x', r'mathcalW': 'x',
+        r'\\pi': 'pi', r'pi': 'pi',  # ✅ prevent pi → ip
+        r'\\mathrm': '', r'mathrm': '',
     }
     for wrong, correct in replacements.items():
         latex = re.sub(wrong, correct, latex)
 
-    # ✅ Fix mathcal and cal variables
     latex = re.sub(r'\\(cal|mathcal)\s*\{?\s*[Xx]\s*\}?', 'x', latex)
     latex = re.sub(r'\\(cal|mathcal)\s*\{?\s*[Yy]\s*\}?', 'y', latex)
     latex = re.sub(r'\\(cal|mathcal)\s*\{?\s*[Zz]\s*\}?', 'z', latex)
+
     latex = latex.replace('cal x', 'x').replace('cal X', 'x')
     latex = latex.replace('mathcal x', 'x').replace('mathcal X', 'x')
 
-    # 🧹 Remove curly braces and trailing punctuation
     latex = latex.replace('{', '').replace('}', '')
-    latex = latex.strip().rstrip(',.') 
-
-    # ✅ Replace symbolic constants and protect them
-    latex = latex.replace(r'\pi', 'SYMPY_PI')  # protect pi
+    latex = latex.strip().rstrip(',.')
     latex = re.sub(r'(?<![a-zA-Z0-9])e(?![a-zA-Z0-9])', 'E', latex)
 
-    # ✅ Add multiplication without breaking pi
-    latex = re.sub(r'(\d)([a-zA-Z])', r'\1*\2', latex)  # 4x → 4*x
+    latex = re.sub(r'(\d)([a-zA-Z])', r'\1*\2', latex)
     latex = re.sub(r'(\d+)\s*i', r'\1*I', latex)
     latex = re.sub(r'(?<![a-zA-Z0-9])i(?![a-zA-Z0-9])', 'I', latex)
     latex = re.sub(r'\(([^()]+?)\)\s*([a-zA-Z](\^\d+)?)', r'(\1)*\2', latex)
 
-    # ✅ Fix symbols
     latex = latex.replace(r'\cdot', '*')
     latex = latex.replace('−', '-')  # Unicode minus
-
-    # ✅ Final cleanup
     latex = re.sub(r'[^\w\s^=+*\-().]', '', latex)
 
-    # ✅ Restore pi
-    latex = latex.replace('SYMPY_PI', 'pi')
-
-    # ✅ Ensure equation
     if '=' not in latex:
         latex += '=0'
 
@@ -75,7 +64,9 @@ def clean_latex(latex):
 
 # Fallback to external LLM microservice
 def request_llm_fallback(bad_latex, llm_url):
-    pre_cleaned = re.sub(r'(\\!?pm|\\not=?|\\!|\\L|\\perp|\\bar|\\Sigma|\\boldmath|G|L(?=\^))', '', bad_latex)
+    pre_cleaned = re.sub(
+        r'(\\!?pm|\\not=?|\\!|\\L|\\perp|\\bar|\\Sigma|\\boldmath|G|L(?=\^))', '', bad_latex
+    )
     try:
         response = requests.post(f"{llm_url}/clean", json={"prompt": pre_cleaned})
         if response.status_code == 200:
@@ -84,7 +75,7 @@ def request_llm_fallback(bad_latex, llm_url):
         print(f"LLM fallback failed: {e}")
     return pre_cleaned
 
-# Explanation
+# Request human-style explanation
 def request_llm_explanation(latex, llm_url):
     try:
         response = requests.post(f"{llm_url}/explain", json={"prompt": latex})
@@ -110,12 +101,15 @@ def solve_polynomial(image, llm_url):
             expr = parse_latex(cleaned_latex)
             if not isinstance(expr, sp.Equality):
                 raise ValueError("Expression is not an equation.")
+
             lhs_minus_rhs = expr.lhs - expr.rhs
             if not lhs_minus_rhs.is_polynomial():
-                raise ValueError("Not a polynomial.")
+                raise ValueError("Expression is not a polynomial.")
+
             junk_symbols = {"pm", "cdot", "mathrm", "boldmath", "bar", "L"}
-            if {str(s) for s in expr.free_symbols} & junk_symbols:
-                raise ValueError("Contains junk.")
+            symbols = {str(s) for s in expr.free_symbols}
+            if symbols & junk_symbols:
+                raise ValueError("Expression contains junk symbols.")
         except Exception:
             fixed_latex = request_llm_fallback(cleaned_latex, llm_url)
             cleaned_latex = clean_latex(fixed_latex)
@@ -125,19 +119,24 @@ def solve_polynomial(image, llm_url):
                     raise ValueError("Expression is not an equation.")
                 lhs_minus_rhs = expr.lhs - expr.rhs
                 if not lhs_minus_rhs.is_polynomial():
-                    raise ValueError("Not a polynomial.")
-                if {str(s) for s in expr.free_symbols} & junk_symbols:
-                    raise ValueError("Contains junk.")
+                    raise ValueError("Expression is not a polynomial.")
+                symbols = {str(s) for s in expr.free_symbols}
+                if symbols & junk_symbols:
+                    raise ValueError("Expression contains junk symbols.")
             except Exception:
                 expr = None
 
         if expr is None:
-            return f"❌ Could not parse even after fallback:\n\n```latex\n{cleaned_latex}\n```", cleaned_latex, ""
+            return (
+                f"❌ Could not parse expression even after fallback:\n\n```latex\n{cleaned_latex}\n```",
+                cleaned_latex,
+                ""
+            )
 
         output = (
-            f"## 📄 Extracted LaTeX\n```latex\n{latex_result}\n```\n"
-            f"\n---\n## 🧹 Cleaned LaTeX Used\n```latex\n{cleaned_latex}\n```\n"
-            f"\n---\n## 🧠 Parsed Expression\n$$ {sp.latex(expr)} $$\n---\n"
+            f"## 📄 Extracted LaTeX\n\n```latex\n{latex_result}\n```\n"
+            f"\n---\n## 🧹 Cleaned LaTeX Used\n\n```latex\n{cleaned_latex}\n```\n"
+            f"\n---\n## 🧠 Parsed Expression\n\n$$ {sp.latex(expr)} $$\n\n---\n"
         )
 
         if isinstance(expr, sp.Equality):
@@ -151,9 +150,10 @@ def solve_polynomial(image, llm_url):
                     x_sym = sym
                     break
             if x_sym is None:
-                raise ValueError("❌ Could not find variable 'x'.")
+                raise ValueError("❌ Could not find variable 'x' in the equation.")
 
             roots = sp.solve(sp.Eq(lhs, 0), x_sym, dict=True)
+
             output += "## ✅ Step 3: Solve Roots\n"
             if roots:
                 output += "$$\n\\begin{aligned}\n"
@@ -173,8 +173,8 @@ def solve_polynomial(image, llm_url):
 
 # Gradio UI
 with gr.Blocks() as demo:
-    llm_url = gr.Textbox(label="🔗 Enter LLM Microservice URL", placeholder="https://xxxx.ngrok-free.app")
-    image_input = gr.Image(type="pil", label="📷 Upload Polynomial Image")
+    llm_url = gr.Textbox(label="🔗 Enter LLM Microservice URL (from Colab)", placeholder="https://xxxx.ngrok-free.app")
+    image_input = gr.Image(type="pil", label="📷 Upload Image of Polynomial")
     output_box = gr.Markdown(label="📋 Step-by-step Solution")
     explain_box = gr.Markdown(label="🗣️ Human-style Explanation")
     hidden_latex = gr.Textbox(visible=False)
@@ -190,7 +190,7 @@ with gr.Blocks() as demo:
     explain_btn.click(fn=request_llm_explanation, inputs=[hidden_latex, llm_url], outputs=explain_box)
 
     demo.title = "🧠 Polynomial Solver from Image"
-    demo.description = "Upload a typed or handwritten polynomial image. View symbolic steps and approximate root solutions."
+    demo.description = "Upload a polynomial image (typed or handwritten). View symbolic steps and human-style explanation."
 
 if __name__ == "__main__":
     demo.launch()