Update app.py

app.py

@@ -36,24 +36,22 @@ def clean_latex(latex):
     for wrong, correct in replacements.items():
         latex = re.sub(wrong, correct, latex)
 
-    # ✅ Fix mathcal and cal variables in all formats
+    # ✅ 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)
-
-    # ✅ Clean OCR artifacts like "cal X"
     latex = latex.replace('cal x', 'x').replace('cal X', 'x')
     latex = latex.replace('mathcal x', 'x').replace('mathcal X', 'x')
 
-    # 🧹 Remove curly braces and punctuation
+    # 🧹 Remove curly braces and trailing punctuation
     latex = latex.replace('{', '').replace('}', '')
-    latex = latex.strip().rstrip(',.')  # remove trailing punctuation
+    latex = latex.strip().rstrip(',.') 
 
-    # ✅ Symbolic constants: keep pi and E as symbols
-    latex = latex.replace(r'\pi', 'pi')
+    # ✅ Replace symbolic constants and protect them
+    latex = latex.replace(r'\pi', 'SYMPY_PI')  # protect pi
     latex = re.sub(r'(?<![a-zA-Z0-9])e(?![a-zA-Z0-9])', 'E', latex)
 
-    # ✅ Add multiplication
+    # ✅ 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+)\s*i', r'\1*I', latex)
     latex = re.sub(r'(?<![a-zA-Z0-9])i(?![a-zA-Z0-9])', 'I', latex)
@@ -66,18 +64,18 @@ def clean_latex(latex):
     # ✅ Final cleanup
     latex = re.sub(r'[^\w\s^=+*\-().]', '', latex)
 
-    # ✅ Ensure it's an equation
+    # ✅ Restore pi
+    latex = latex.replace('SYMPY_PI', 'pi')
+
+    # ✅ Ensure equation
     if '=' not in latex:
         latex += '=0'
 
     return 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:
@@ -86,7 +84,7 @@ def request_llm_fallback(bad_latex, llm_url):
         print(f"LLM fallback failed: {e}")
     return pre_cleaned
 
-# NEW: Request human-style explanation
+# Explanation
 def request_llm_explanation(latex, llm_url):
     try:
         response = requests.post(f"{llm_url}/explain", json={"prompt": latex})
@@ -97,7 +95,7 @@ def request_llm_explanation(latex, llm_url):
     except Exception as e:
         return f"❌ LLM explanation error: {e}"
 
-# Main function
+# Main solver
 def solve_polynomial(image, llm_url):
     try:
         img = preprocess_handwritten_image(image)
@@ -110,19 +108,14 @@ def solve_polynomial(image, llm_url):
 
         try:
             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("Expression is not a polynomial.")
-
+                raise ValueError("Not a polynomial.")
             junk_symbols = {"pm", "cdot", "mathrm", "boldmath", "bar", "L"}
-            symbols = {str(s) for s in expr.free_symbols}
-            if symbols & junk_symbols:
-                raise ValueError("Expression contains junk symbols.")
-
+            if {str(s) for s in expr.free_symbols} & junk_symbols:
+                raise ValueError("Contains junk.")
         except Exception:
             fixed_latex = request_llm_fallback(cleaned_latex, llm_url)
             cleaned_latex = clean_latex(fixed_latex)
@@ -130,29 +123,21 @@ 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("Expression is not a polynomial.")
-
-                symbols = {str(s) for s in expr.free_symbols}
-                if symbols & junk_symbols:
-                    raise ValueError("Expression contains junk symbols.")
-
+                    raise ValueError("Not a polynomial.")
+                if {str(s) for s in expr.free_symbols} & junk_symbols:
+                    raise ValueError("Contains junk.")
             except Exception:
                 expr = None
 
         if expr is None:
-            return (
-                f"❌ Could not parse expression even after fallback:\n\n```latex\n{cleaned_latex}\n```",
-                cleaned_latex,
-                ""
-            )
+            return f"❌ Could not parse even after fallback:\n\n```latex\n{cleaned_latex}\n```", cleaned_latex, ""
 
         output = (
-            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"
+            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"
         )
 
         if isinstance(expr, sp.Equality):
@@ -160,17 +145,15 @@ def solve_polynomial(image, llm_url):
             output += f"## ✏️ Step 1: Standard Form\n$$ {sp.latex(lhs)} = 0 $$\n---\n"
             output += f"## 🧩 Step 2: Factor\n$$ {sp.latex(sp.factor(lhs))} = 0 $$\n---\n"
 
-            # ✅ SOLVE FOR x BY NAME ONLY
             x_sym = None
             for sym in lhs.free_symbols:
                 if str(sym) == "x":
                     x_sym = sym
                     break
             if x_sym is None:
-                raise ValueError("❌ Could not find variable 'x' in the equation.")
+                raise ValueError("❌ Could not find variable 'x'.")
 
             roots = sp.solve(sp.Eq(lhs, 0), x_sym, dict=True)
-
             output += "## ✅ Step 3: Solve Roots\n"
             if roots:
                 output += "$$\n\\begin{aligned}\n"
@@ -187,11 +170,11 @@ def solve_polynomial(image, llm_url):
 
     except Exception as e:
         return f"❌ **Error**: {str(e)}", "", ""
-        
-# UI
+
+# Gradio UI
 with gr.Blocks() as demo:
-    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")
+    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")
     output_box = gr.Markdown(label="📋 Step-by-step Solution")
     explain_box = gr.Markdown(label="🗣️ Human-style Explanation")
     hidden_latex = gr.Textbox(visible=False)
@@ -207,7 +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 polynomial image (typed or handwritten). View symbolic steps and human-style explanation."
+    demo.description = "Upload a typed or handwritten polynomial image. View symbolic steps and approximate root solutions."
 
 if __name__ == "__main__":
     demo.launch()