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https://issues.apache.org/jira/browse/MAHOUT-681?focusedWorklogId=995102&page=com.atlassian.jira.plugin.system.issuetabpanels:worklog-tabpanel#worklog-995102
 ]

ASF GitHub Bot logged work on MAHOUT-681:
-----------------------------------------

                Author: ASF GitHub Bot
            Created on: 08/Dec/25 04:51
            Start Date: 08/Dec/25 04:51
    Worklog Time Spent: 10m 
      Work Description: Copilot commented on code in PR #693:
URL: https://github.com/apache/mahout/pull/693#discussion_r2597029402


##########
qumat/qumat.py:
##########
@@ -251,6 +251,20 @@ def apply_pauli_z_gate(self, qubit_index):
         self._validate_qubit_index(qubit_index)
         self.backend_module.apply_pauli_z_gate(self.circuit, qubit_index)
 
+    def apply_t_gate(self, qubit_index):
+        """Apply a T-gate (π/8 gate) to the specified qubit.
+
+        Applies a π/4 phase shift to the qubit. Essential for universal
+        quantum computation when combined with Hadamard and CNOT gates.

Review Comment:
   The docstring incorrectly states "Applies a π/4 phase shift" but the T-gate 
actually applies a π/4 phase to the |1⟩ state, not a π/4 phase shift to the 
overall state. More accurately, the T-gate can be described as applying a 
relative phase of π/4 or introducing a phase of e^(iπ/4) = e^(i45°) to the |1⟩ 
state. The phase shift terminology is potentially misleading.
   ```suggestion
           Applies a relative phase of π/4 (i.e., multiplies the |1⟩ state by 
e^(iπ/4)).
           Essential for universal quantum computation when combined with 
Hadamard and CNOT gates.
   ```



##########
qumat/qumat.py:
##########
@@ -251,6 +251,20 @@ def apply_pauli_z_gate(self, qubit_index):
         self._validate_qubit_index(qubit_index)
         self.backend_module.apply_pauli_z_gate(self.circuit, qubit_index)
 
+    def apply_t_gate(self, qubit_index):
+        """Apply a T-gate (π/8 gate) to the specified qubit.
+
+        Applies a π/4 phase shift to the qubit. Essential for universal
+        quantum computation when combined with Hadamard and CNOT gates.
+
+        :param qubit_index: Index of the qubit.
+        :type qubit_index: int
+        :raises RuntimeError: If the circuit has not been initialized.
+        """
+        self._ensure_circuit_initialized()
+        self._validate_qubit_index(qubit_index)
+        self.backend_module.apply_t_gate(self.circuit, qubit_index)

Review Comment:
   The newly added `apply_t_gate` method lacks test coverage. The test file 
`testing/test_single_qubit_gates.py` has comprehensive test classes for all 
other single-qubit gates (TestPauliXGate, TestPauliYGate, TestPauliZGate, 
TestHadamardGate, TestNOTGate, TestUGate), but no `TestTGate` class exists. 
Consider adding a test class similar to the existing ones that verifies:
   1. T-gate state transitions (e.g., T|0⟩ = |0⟩, T|1⟩ applies phase)
   2. T-gate phase accumulation (T^8 = I)
   3. Cross-backend consistency
   4. Combination with Hadamard to verify phase effect





Issue Time Tracking
-------------------

    Worklog Id:     (was: 995102)
    Time Spent: 0.5h  (was: 20m)

> Remove AsymmetricSampledNormal, SampledNormal, L1, Normal Models and 
> Distributions
> ----------------------------------------------------------------------------------
>
>                 Key: MAHOUT-681
>                 URL: https://issues.apache.org/jira/browse/MAHOUT-681
>             Project: Mahout
>          Issue Type: Improvement
>          Components: classic
>    Affects Versions: 0.4
>            Reporter: Sean R. Owen
>            Assignee: Jeff Eastman
>            Priority: Minor
>             Fix For: 0.5
>
>         Attachments: MAHOUT-681.patch
>
>          Time Spent: 0.5h
>  Remaining Estimate: 0h
>
> As discussed on the mailing list, it looks like these classes are deprecated, 
> and actually unused outside of tests. Here's my proposal to remove them.



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