From b6d3486adcfb22c838bc65631e55f783a6380155 Mon Sep 17 00:00:00 2001
From: Shruti Patel <shrutipatel@meta.com>
Date: Fri, 30 Jan 2026 10:52:26 -0800
Subject: [PATCH] Handle all-infeasible traces in UtilityProgressionAnalysis
 (#4837)

Summary:

When `get_trace` returns all infeasible points (represented as `inf` or `-inf` values), the utility progression plot would previously attempt to plot these infinite values. This change adds a check to raise an `ExperimentNotReadyError` with a clear message when all trials are infeasible, preventing the plot from displaying meaningless data.

Differential Revision: D91751120
---
 .../plotly/tests/test_utility_progression.py  | 19 +++++++++++++++++++
 ax/analysis/plotly/utility_progression.py     |  8 ++++++++
 2 files changed, 27 insertions(+)

diff --git a/ax/analysis/plotly/tests/test_utility_progression.py b/ax/analysis/plotly/tests/test_utility_progression.py
index bf697753e1e..cfaf90e214e 100644
--- a/ax/analysis/plotly/tests/test_utility_progression.py
+++ b/ax/analysis/plotly/tests/test_utility_progression.py
@@ -5,12 +5,16 @@
 
 # pyre-strict
 
+import math
+from unittest.mock import patch
+
 from ax.analysis.plotly.plotly_analysis import PlotlyAnalysisCard
 from ax.analysis.plotly.utility_progression import UtilityProgressionAnalysis
 from ax.core.auxiliary import AuxiliaryExperiment, AuxiliaryExperimentPurpose
 from ax.core.metric import Metric
 from ax.core.objective import MultiObjective, Objective
 from ax.core.optimization_config import PreferenceOptimizationConfig
+from ax.exceptions.core import ExperimentNotReadyError
 from ax.utils.common.testutils import TestCase
 from ax.utils.testing.core_stubs import (
     get_branin_experiment,
@@ -199,3 +203,18 @@ def test_scalarized_objective_support(self) -> None:
 
         # Assert: Check that title/subtitle show the formula
         self.assertIn("formula:", card.subtitle)
+
+    def test_all_infeasible_points_raises_error(self) -> None:
+        """Test that an error is raised when all points are infeasible."""
+        experiment = get_branin_experiment(with_completed_trial=True)
+
+        with (
+            patch(
+                "ax.analysis.plotly.utility_progression.get_trace",
+                return_value=[math.inf, -math.inf, math.inf],
+            ),
+            self.assertRaises(ExperimentNotReadyError) as cm,
+        ):
+            self.analysis.compute(experiment=experiment)
+
+        self.assertIn("infeasible", str(cm.exception).lower())
diff --git a/ax/analysis/plotly/utility_progression.py b/ax/analysis/plotly/utility_progression.py
index 2653cbf7d28..b9f7df7d668 100644
--- a/ax/analysis/plotly/utility_progression.py
+++ b/ax/analysis/plotly/utility_progression.py
@@ -7,6 +7,7 @@
 
 from typing import final
 
+import numpy as np
 import pandas as pd
 import plotly.express as px
 from ax.adapter.base import Adapter
@@ -113,6 +114,13 @@ def compute(
                 "constraints."
             )
 
+        # Check if all points are infeasible (inf or -inf values)
+        if all(np.isinf(value) for value in trace):
+            raise ExperimentNotReadyError(
+                "All trials in the utility trace are infeasible (violate outcome "
+                "constraints). No feasible points to plot."
+            )
+
         # Create DataFrame with 1-based trace index for user-friendly display
         # (1st completed trial, 2nd completed trial, etc. instead of 0-indexed)
         df = pd.DataFrame(