Update app.py

app.py

@@ -9,7 +9,6 @@ import traceback
 # --- FIX for CSV Field Size Limit ---
 # Increase the CSV field size limit to handle large Plotly JSON objects that are
 # generated when Gradio's Examples component tries to log the output.
-# This is the most robust way to set the limit to the maximum supported by the system.
 max_int = sys.maxsize
 while True:
     try:
@@ -30,9 +29,9 @@ def solve_and_plot_interactive(Lx: float,
                                initial: str = "gaussian",
                                bc: str = "dirichlet"):
     """
-    Solves the 2D heat equation and returns an interactive Plotly figure.
+    Solves the 2D heat equation and returns an interactive Plotly figure with a fixed axis range.
     """
-    # --- 1. Simulation Setup ---
+    # --- 1. Simulation Setup (No changes here) ---
     x = np.linspace(0, Lx, Nx)
     y = np.linspace(0, Ly, Ny)
     dx, dy = x[1] - x[0], y[1] - y[0]
@@ -52,7 +51,7 @@ def solve_and_plot_interactive(Lx: float,
     elif initial == "step":
         u = np.where((X < Lx/2) & (Y < Ly/2), 1.0, 0.0)
 
-    # --- 2. Solve the Heat Equation ---
+    # --- 2. Solve the Heat Equation (No changes here) ---
     time_indices = np.linspace(0, Nt - 1, M, dtype=int)
     U_slider = np.zeros((M, Nx, Ny))
     store_idx = 0
@@ -79,6 +78,15 @@ def solve_and_plot_interactive(Lx: float,
             store_idx += 1
             
     # --- 3. Create a Plotly Figure for Web ---
+
+    # --- FIX: Calculate the global min/max temperature for a fixed Z-axis range ---
+    z_min = U_slider.min()
+    z_max = U_slider.max()
+    # Add a tiny buffer if the data is completely flat to avoid a display error
+    if z_max == z_min:
+        z_max += 1e-9
+    # --------------------------------------------------------------------------------
+            
     points_2d = np.vstack([X.ravel(), Y.ravel()]).T
     tri = Delaunay(points_2d)
     
@@ -93,12 +101,17 @@ def solve_and_plot_interactive(Lx: float,
                 i=tri.simplices[:, 0], j=tri.simplices[:, 1], k=tri.simplices[:, 2],
                 intensity=z_data,
                 colorscale='Viridis',
+                # --- FIX: Set the intensity range to the global min/max for a consistent color bar ---
+                cmin=z_min,
+                cmax=z_max,
+                # -------------------------------------------------------------------------------------
                 name=f'Time: {time_value:.2f}s',
                 showscale=True if i == 0 else False,
                 visible=(i == 0)
             )
         )
 
+    # Slider creation logic is unchanged
     steps = []
     for i in range(len(fig.data)):
         time_value = (time_indices[i] / (Nt-1)) * t_max if Nt > 1 else 0
@@ -112,16 +125,26 @@ def solve_and_plot_interactive(Lx: float,
 
     sliders = [dict(active=0, currentvalue={"prefix": "Time: "}, pad={"t": 50}, steps=steps)]
 
+    # --- FIX: Update the layout to use the fixed axis ranges ---
     fig.update_layout(
         title=f'2D Heat Eq — init={initial}, bc={bc}',
-        scene=dict(xaxis_title='X', yaxis_title='Y', zaxis_title='Temperature'),
+        scene=dict(
+            xaxis_title='X',
+            yaxis_title='Y',
+            zaxis_title='Temperature',
+            # Set the axis ranges to be fixed across all animation frames
+            xaxis=dict(range=[0, Lx]),
+            yaxis=dict(range=[0, Ly]),
+            zaxis=dict(range=[z_min, z_max]),
+        ),
         sliders=sliders
     )
+    # -------------------------------------------------------------
     
     return fig
 
 
-# --- Gradio Interface Function with Error Handling ---
+# --- Gradio Interface Function with Error Handling (No changes here) ---
 def gradio_interface(lx, ly, t_max, m_steps, gamma, nx, ny, initial, bc):
     try:
         nx, ny, m_steps = int(nx), int(ny), int(m_steps)
@@ -139,7 +162,7 @@ def gradio_interface(lx, ly, t_max, m_steps, gamma, nx, ny, initial, bc):
         )
         return error_fig
 
-# --- Gradio UI Definition ---
+# --- Gradio UI Definition (No changes here) ---
 with gr.Blocks(theme=gr.themes.Soft(), title="2D Heat Simulator") as demo:
     gr.Markdown("# ♨️ 2D Heat Equation Simulator")
     gr.Markdown("Adjust parameters and click 'Run' to generate an interactive plot directly in your browser.")