Fix display of register names with multiple underscores in mpl and latex drawers

qiskit/visualization/matplotlib.py

@@ -451,23 +451,18 @@ def _get_bit_labels(self):
         initial_qbit = " |0>" if self._initial_state else ""
         initial_cbit = " 0" if self._initial_state else ""
 
-        def _fix_double_script(bit_label):
-            words = bit_label.split(" ")
-            words = [word.replace("_", r"\_") if word.count("_") > 1 else word for word in words]
-            words = [
-                word.replace("^", r"\^{\ }") if word.count("^") > 1 else word for word in words
-            ]
-            bit_label = " ".join(words).replace(" ", "\\;")
-            return bit_label
-
         # quantum register
         for ii, reg in enumerate(self._qubits):
             register = self._bit_locations[reg]["register"]
             index = self._bit_locations[reg]["index"]
+            reg_size = 0 if register is None else register.size
             qubit_label = get_bit_label("mpl", register, index, qubit=True, layout=self._layout)
-            qubit_label = "$" + _fix_double_script(qubit_label) + "$" + initial_qbit
+            qubit_label = "$" + qubit_label + "$" + initial_qbit
 
-            text_width = self._get_text_width(qubit_label, self._fs) * 1.15
+            reg_single = 0 if reg_size < 2 else 1
+            text_width = (
+                self._get_text_width(qubit_label, self._fs, reg_to_remove=reg_single) * 1.15
+            )
             if text_width > longest_bit_label_width:
                 longest_bit_label_width = text_width
             pos = -ii
@@ -487,6 +482,7 @@ def _fix_double_script(bit_label):
             for ii, reg in enumerate(self._clbits):
                 register = self._bit_locations[reg]["register"]
                 index = self._bit_locations[reg]["index"]
+                reg_size = 0 if register is None else register.size
                 if register is None or not self._cregbundle or prev_creg != register:
                     n_lines += 1
                     idx += 1
@@ -495,12 +491,14 @@ def _fix_double_script(bit_label):
                 clbit_label = get_bit_label(
                     "mpl", register, index, qubit=False, cregbundle=self._cregbundle
                 )
-                clbit_label = _fix_double_script(clbit_label)
                 if register is None or not self._cregbundle:
                     clbit_label = "$" + clbit_label + "$"
                 clbit_label += initial_cbit
 
-                text_width = self._get_text_width(clbit_label, self._fs) * 1.15
+                reg_single = 0 if reg_size < 2 or self._cregbundle else 1
+                text_width = (
+                    self._get_text_width(clbit_label, self._fs, reg_to_remove=reg_single) * 1.15
+                )
                 if text_width > longest_bit_label_width:
                     longest_bit_label_width = text_width
                 pos = y_off - idx
@@ -579,7 +577,7 @@ def _get_coords(self, n_lines):
         anchors = [self._q_anchors[ii].get_index() for ii in self._qubits_dict]
         return max(anchors) if anchors else 0
 
-    def _get_text_width(self, text, fontsize, param=False):
+    def _get_text_width(self, text, fontsize, param=False, reg_to_remove=None):
         """Compute the width of a string in the default font"""
         if not text:
             return 0.0
@@ -596,6 +594,11 @@ def _get_text_width(self, text, fontsize, param=False):
         # If there are subscripts or superscripts in mathtext string
         # we need to account for that spacing by manually removing
         # from text string for text length
+
+        # if it's a register and there's a subscript at the end,
+        # remove 1 underscore, otherwise don't remove any
+        if reg_to_remove is not None:
+            num_underscores = reg_to_remove
         if num_underscores:
             text = text.replace("_", "", num_underscores)
         if num_carets:

qiskit/visualization/utils.py

@@ -185,14 +185,18 @@ def get_bit_label(drawer, register, index, qubit=True, layout=None, cregbundle=T
         reg_name = f"{register.name}"
         reg_name_index = f"{register.name}_{index}"
     else:
-        reg_name = f"{{{register.name}}}"
-        reg_name_index = f"{{{register.name}}}_{{{index}}}"
+        reg_name = f"{{{fix_special_characters(register.name)}}}"
+        reg_name_index = f"{reg_name}_{{{index}}}"
 
     # Clbits
     if not qubit:
-        if cregbundle:
+        if cregbundle and drawer != "latex":
             bit_label = f"{register.name}"
-        elif register.size == 1:
+            return bit_label
+
+        size = register.size
+        if size == 1 or cregbundle:
+            size = 1
             bit_label = reg_name
         else:
             bit_label = reg_name_index
@@ -218,6 +222,8 @@ def get_bit_label(drawer, register, index, qubit=True, layout=None, cregbundle=T
                 bit_label = f"{virt_bit} -> {index}"
             else:
                 bit_label = f"{{{virt_bit}}} \\mapsto {{{index}}}"
+        if drawer != "text":
+            bit_label = bit_label.replace(" ", "\\;")  # use wider spaces
     else:
         bit_label = index_str
 
@@ -272,6 +278,22 @@ def get_condition_label(condition, clbits, bit_locations, cregbundle):
     return label, clbit_mask, vlist
 
 
+def fix_special_characters(label):
+    """
+    Convert any special characters for mpl and latex drawers.
+    Currently only checks for multiple underscores in register names
+    and uses wider space for mpl and latex drawers.
+
+    Args:
+        label (str): the label to fix
+
+    Returns:
+        str: label to display
+    """
+    label = label.replace("_", r"\_").replace(" ", "\\;")
+    return label
+
+
 def generate_latex_label(label):
     """Convert a label to a valid latex string."""
     if not HAS_PYLATEX:

releasenotes/notes/fix-multi-underscore-display-37b900195ca3d2c5.yaml

@@ -0,0 +1,7 @@
+---
+fixes:
+  - |
+    Fixes a problem in the ``mpl`` circuit drawer when register names
+    with multiple underscores in the name did not display correctly.
+    Also the same problem would cause the ``latex`` drawer to fail,
+    which has been fixed.

test/ipynb/mpl/circuit/test_circuit_matplotlib_drawer.py

@@ -221,6 +221,17 @@ def test_long_name(self):
 
         self.circuit_drawer(circuit, filename="long_name.png")
 
+    def test_multi_underscore_reg_names(self):
+        """Test that multi-underscores in register names display properly"""
+        q_reg1 = QuantumRegister(1, "q1_re__g__g")
+        q_reg3 = QuantumRegister(3, "q3_re_g__g")
+        c_reg1 = ClassicalRegister(1, "c1_re_g__g")
+        c_reg3 = ClassicalRegister(3, "c3_re_g__g")
+        circuit = QuantumCircuit(q_reg1, q_reg3, c_reg1, c_reg3)
+
+        self.circuit_drawer(circuit, cregbundle=True, filename="multi_underscore_true.png")
+        self.circuit_drawer(circuit, cregbundle=False, filename="multi_underscore_false.png")
+
     def test_conditional(self):
         """Test that circuits with conditionals draw correctly"""
         qr = QuantumRegister(2, "q")

test/python/visualization/references/test_latex_4597.tex

@@ -9,6 +9,6 @@
 	 	\nghost{{q}_{0} :  } & \lstick{{q}_{0} :  } & \qw & \qw & \qw & \qw\\
 	 	\nghost{{q}_{1} :  } & \lstick{{q}_{1} :  } & \qw & \qw & \qw & \qw\\
 	 	\nghost{{q}_{2} :  } & \lstick{{q}_{2} :  } & \qw & \gate{\mathrm{X}} & \qw & \qw\\
-	 	\nghost{\mathrm{c :  }} & \lstick{\mathrm{c :  }} & \lstick{/_{_{3}}} \cw & \control \cw^(0.0){^{\mathtt{0x2}}} \cwx[-1] & \cw & \cw\\
+	 	\nghost{\mathrm{{c} :  }} & \lstick{\mathrm{{c} :  }} & \lstick{/_{_{3}}} \cw & \control \cw^(0.0){^{\mathtt{0x2}}} \cwx[-1] & \cw & \cw\\
 \\ }}
 \end{document}

test/python/visualization/references/test_latex_cif_single_bit_bundle.tex

@@ -8,6 +8,6 @@
 \Qcircuit @C=1.0em @R=0.2em @!R { \\
 	 	\nghost{{qr}_{0} :  } & \lstick{{qr}_{0} :  } & \qw & \gate{\mathrm{H}} & \qw & \qw & \qw\\
 	 	\nghost{{qr}_{1} :  } & \lstick{{qr}_{1} :  } & \qw & \qw & \gate{\mathrm{X}} & \qw & \qw\\
-	 	\nghost{\mathrm{cr :  }} & \lstick{\mathrm{cr :  }} & \lstick{/_{_{2}}} \cw & \controlo \cw^(0.0){^{\mathtt{cr_1=0x0}}} \cwx[-2] & \control \cw^(0.0){^{\mathtt{cr_0=0x1}}} \cwx[-1] & \cw & \cw\\
+	 	\nghost{\mathrm{{cr} :  }} & \lstick{\mathrm{{cr} :  }} & \lstick{/_{_{2}}} \cw & \controlo \cw^(0.0){^{\mathtt{cr_1=0x0}}} \cwx[-2] & \control \cw^(0.0){^{\mathtt{cr_0=0x1}}} \cwx[-1] & \cw & \cw\\
 \\ }}
 \end{document}

test/python/visualization/references/test_latex_conditional.tex

@@ -8,6 +8,6 @@
 \Qcircuit @C=1.0em @R=0.2em @!R { \\
 	 	\nghost{{q}_{0} :  } & \lstick{{q}_{0} :  } & \gate{\mathrm{H}} & \meter & \qw & \gate{\mathrm{H}} & \qw & \qw\\
 	 	\nghost{{q}_{1} :  } & \lstick{{q}_{1} :  } & \gate{\mathrm{H}} & \qw & \meter & \qw & \qw & \qw\\
-	 	\nghost{\mathrm{c :  }} & \lstick{\mathrm{c :  }} & \lstick{/_{_{2}}} \cw & \dstick{_{_{\hspace{0.0em}0}}} \cw \ar @{<=} [-2,0] & \dstick{_{_{\hspace{0.0em}1}}} \cw \ar @{<=} [-1,0] & \control \cw^(0.0){^{\mathtt{0x2}}} \cwx[-2] & \cw & \cw\\
+	 	\nghost{\mathrm{{c} :  }} & \lstick{\mathrm{{c} :  }} & \lstick{/_{_{2}}} \cw & \dstick{_{_{\hspace{0.0em}0}}} \cw \ar @{<=} [-2,0] & \dstick{_{_{\hspace{0.0em}1}}} \cw \ar @{<=} [-1,0] & \control \cw^(0.0){^{\mathtt{0x2}}} \cwx[-2] & \cw & \cw\\
 \\ }}
 \end{document}

test/python/visualization/references/test_latex_creg_initial_true.tex

@@ -8,6 +8,6 @@
 \Qcircuit @C=1.0em @R=0.2em @!R { \\
 	 	\nghost{{q}_{0} : \ket{{0}} } & \lstick{{q}_{0} : \ket{{0}} } & \gate{\mathrm{X}} & \gate{\mathrm{H}} & \qw & \qw\\
 	 	\nghost{{q}_{1} : \ket{{0}} } & \lstick{{q}_{1} : \ket{{0}} } & \gate{\mathrm{X}} & \qw & \qw & \qw\\
-	 	\nghost{\mathrm{c : 0 }} & \lstick{\mathrm{c : 0 }} & \lstick{/_{_{2}}} \cw & \cw & \cw & \cw\\
+	 	\nghost{\mathrm{{c} : 0 }} & \lstick{\mathrm{{c} : 0 }} & \lstick{/_{_{2}}} \cw & \cw & \cw & \cw\\
 \\ }}
 \end{document}

test/python/visualization/references/test_latex_meas_cond_bits_true.tex

@@ -10,8 +10,8 @@
 	 	\nghost{{1} :  } & \lstick{{1} :  } & \qw & \qw & \qw & \qw & \qw\\
 	 	\nghost{\mathrm{{0} :  }} & \lstick{\mathrm{{0} :  }} & \cw & \cw & \cw & \cw & \cw\\
 	 	\nghost{\mathrm{{1} :  }} & \lstick{\mathrm{{1} :  }} & \cw & \cw & \dstick{_{_{\hspace{0.0em}}}} \cw \ar @{<=} [-3,0] & \cw & \cw\\
-	 	\nghost{\mathrm{cr :  }} & \lstick{\mathrm{cr :  }} & \lstick{/_{_{2}}} \cw & \cw & \cw & \cw & \cw\\
+	 	\nghost{\mathrm{{cr} :  }} & \lstick{\mathrm{{cr} :  }} & \lstick{/_{_{2}}} \cw & \cw & \cw & \cw & \cw\\
 	 	\nghost{\mathrm{{4} :  }} & \lstick{\mathrm{{4} :  }} & \cw & \cw & \cw & \cw & \cw\\
-	 	\nghost{\mathrm{cs :  }} & \lstick{\mathrm{cs :  }} & \lstick{/_{_{3}}} \cw & \controlo \cw^(0.0){^{\mathtt{cs_1=0x0}}} \cwx[-6] & \cw & \cw & \cw\\
+	 	\nghost{\mathrm{{cs} :  }} & \lstick{\mathrm{{cs} :  }} & \lstick{/_{_{3}}} \cw & \controlo \cw^(0.0){^{\mathtt{cs_1=0x0}}} \cwx[-6] & \cw & \cw & \cw\\
 \\ }}
 \end{document}

test/python/visualization/references/test_latex_meas_cond_true.tex

@@ -8,7 +8,7 @@
 \Qcircuit @C=1.0em @R=0.2em @!R { \\
 	 	\nghost{{qr}_{0} :  } & \lstick{{qr}_{0} :  } & \gate{\mathrm{H}} & \meter & \qw & \gate{\mathrm{H}} & \qw & \qw\\
 	 	\nghost{{qr}_{1} :  } & \lstick{{qr}_{1} :  } & \gate{\mathrm{H}} & \qw & \meter & \qw & \qw & \qw\\
-	 	\nghost{\mathrm{cr1 :  }} & \lstick{\mathrm{cr1 :  }} & \lstick{/_{_{2}}} \cw & \dstick{_{_{\hspace{0.0em}1}}} \cw \ar @{<=} [-2,0] & \control \cw^(-0.3){^{\mathtt{0x1}}} \cwx[-1] & \cw & \cw & \cw\\
-	 	\nghost{\mathrm{cr2 :  }} & \lstick{\mathrm{cr2 :  }} & \lstick{/_{_{2}}} \cw & \cw & \dstick{_{_{\hspace{1.5em}0}}} \cw \ar @{<=} [-2,0] & \control \cw^(0.0){^{\mathtt{0x3}}} \cwx[-3] & \cw & \cw\\
+	 	\nghost{\mathrm{{cr1} :  }} & \lstick{\mathrm{{cr1} :  }} & \lstick{/_{_{2}}} \cw & \dstick{_{_{\hspace{0.0em}1}}} \cw \ar @{<=} [-2,0] & \control \cw^(-0.3){^{\mathtt{0x1}}} \cwx[-1] & \cw & \cw & \cw\\
+	 	\nghost{\mathrm{{cr2} :  }} & \lstick{\mathrm{{cr2} :  }} & \lstick{/_{_{2}}} \cw & \cw & \dstick{_{_{\hspace{1.5em}0}}} \cw \ar @{<=} [-2,0] & \control \cw^(0.0){^{\mathtt{0x3}}} \cwx[-3] & \cw & \cw\\
 \\ }}
 \end{document}

test/python/visualization/references/test_latex_meas_condition.tex

@@ -8,6 +8,6 @@
 \Qcircuit @C=1.0em @R=0.2em @!R { \\
 	 	\nghost{{qr}_{0} :  } & \lstick{{qr}_{0} :  } & \gate{\mathrm{H}} & \meter & \qw & \qw & \qw\\
 	 	\nghost{{qr}_{1} :  } & \lstick{{qr}_{1} :  } & \qw & \qw & \gate{\mathrm{H}} & \qw & \qw\\
-	 	\nghost{\mathrm{cr :  }} & \lstick{\mathrm{cr :  }} & \lstick{/_{_{2}}} \cw & \dstick{_{_{\hspace{0.0em}0}}} \cw \ar @{<=} [-2,0] & \control \cw^(0.0){^{\mathtt{0x1}}} \cwx[-1] & \cw & \cw\\
+	 	\nghost{\mathrm{{cr} :  }} & \lstick{\mathrm{{cr} :  }} & \lstick{/_{_{2}}} \cw & \dstick{_{_{\hspace{0.0em}0}}} \cw \ar @{<=} [-2,0] & \control \cw^(0.0){^{\mathtt{0x1}}} \cwx[-1] & \cw & \cw\\
 \\ }}
 \end{document}

test/python/visualization/references/test_latex_multi_underscore_false.tex

@@ -0,0 +1,18 @@
+\documentclass[border=2px]{standalone}
+
+\usepackage[braket, qm]{qcircuit}
+\usepackage{graphicx}
+
+\begin{document}
+\scalebox{1.0}{
+\Qcircuit @C=1.0em @R=1.0em @!R { \\
+	 	\nghost{{q1\_re\_\_g\_\_g} :  } & \lstick{{q1\_re\_\_g\_\_g} :  } & \qw & \qw\\
+	 	\nghost{{q3\_re\_g\_\_g}_{0} :  } & \lstick{{q3\_re\_g\_\_g}_{0} :  } & \qw & \qw\\
+	 	\nghost{{q3\_re\_g\_\_g}_{1} :  } & \lstick{{q3\_re\_g\_\_g}_{1} :  } & \qw & \qw\\
+	 	\nghost{{q3\_re\_g\_\_g}_{2} :  } & \lstick{{q3\_re\_g\_\_g}_{2} :  } & \qw & \qw\\
+	 	\nghost{{c1\_re\_g\_\_g} :  } & \lstick{{c1\_re\_g\_\_g} :  } & \cw & \cw\\
+	 	\nghost{{c3\_re\_g\_\_g}_{0} :  } & \lstick{{c3\_re\_g\_\_g}_{0} :  } & \cw & \cw\\
+	 	\nghost{{c3\_re\_g\_\_g}_{1} :  } & \lstick{{c3\_re\_g\_\_g}_{1} :  } & \cw & \cw\\
+	 	\nghost{{c3\_re\_g\_\_g}_{2} :  } & \lstick{{c3\_re\_g\_\_g}_{2} :  } & \cw & \cw\\
+\\ }}
+\end{document}

test/python/visualization/references/test_latex_multi_underscore_true.tex

@@ -0,0 +1,16 @@
+\documentclass[border=2px]{standalone}
+
+\usepackage[braket, qm]{qcircuit}
+\usepackage{graphicx}
+
+\begin{document}
+\scalebox{1.0}{
+\Qcircuit @C=1.0em @R=1.0em @!R { \\
+	 	\nghost{{q1\_re\_\_g\_\_g} :  } & \lstick{{q1\_re\_\_g\_\_g} :  } & \qw & \qw\\
+	 	\nghost{{q3\_re\_g\_\_g}_{0} :  } & \lstick{{q3\_re\_g\_\_g}_{0} :  } & \qw & \qw\\
+	 	\nghost{{q3\_re\_g\_\_g}_{1} :  } & \lstick{{q3\_re\_g\_\_g}_{1} :  } & \qw & \qw\\
+	 	\nghost{{q3\_re\_g\_\_g}_{2} :  } & \lstick{{q3\_re\_g\_\_g}_{2} :  } & \qw & \qw\\
+	 	\nghost{\mathrm{{c1\_re\_g\_\_g} :  }} & \lstick{\mathrm{{c1\_re\_g\_\_g} :  }} & \lstick{/_{_{1}}} \cw & \cw\\
+	 	\nghost{\mathrm{{c3\_re\_g\_\_g} :  }} & \lstick{\mathrm{{c3\_re\_g\_\_g} :  }} & \lstick{/_{_{3}}} \cw & \cw\\
+\\ }}
+\end{document}

test/python/visualization/references/test_latex_no_barriers_false.tex

@@ -8,6 +8,6 @@
 \Qcircuit @C=1.0em @R=0.2em @!R { \\
 	 	\nghost{{q}_{0} :  } & \lstick{{q}_{0} :  } & \gate{\mathrm{H}} & \qw & \qw\\
 	 	\nghost{{q}_{1} :  } & \lstick{{q}_{1} :  } & \gate{\mathrm{H}} & \qw & \qw\\
-	 	\nghost{\mathrm{c :  }} & \lstick{\mathrm{c :  }} & \lstick{/_{_{2}}} \cw & \cw & \cw\\
+	 	\nghost{\mathrm{{c} :  }} & \lstick{\mathrm{{c} :  }} & \lstick{/_{_{2}}} \cw & \cw & \cw\\
 \\ }}
 \end{document}

test/python/visualization/references/test_latex_no_ops.tex

@@ -8,6 +8,6 @@
 \Qcircuit @C=1.0em @R=1.0em @!R { \\
 	 	\nghost{{q}_{0} :  } & \lstick{{q}_{0} :  } & \qw & \qw\\
 	 	\nghost{{q}_{1} :  } & \lstick{{q}_{1} :  } & \qw & \qw\\
-	 	\nghost{\mathrm{c :  }} & \lstick{\mathrm{c :  }} & \lstick{/_{_{3}}} \cw & \cw\\
+	 	\nghost{\mathrm{{c} :  }} & \lstick{\mathrm{{c} :  }} & \lstick{/_{_{3}}} \cw & \cw\\
 \\ }}
 \end{document}

test/python/visualization/references/test_latex_partial_layout.tex

@@ -6,10 +6,10 @@
 \begin{document}
 \scalebox{1.0}{
 \Qcircuit @C=1.0em @R=0.2em @!R { \\
-	 	\nghost{{q}_{2} \mapsto {0} :  } & \lstick{{q}_{2} \mapsto {0} :  } & \qw & \qw & \qw\\
-	 	\nghost{{q}_{0} \mapsto {1} :  } & \lstick{{q}_{0} \mapsto {1} :  } & \qw & \qw & \qw\\
-	 	\nghost{{q}_{1} \mapsto {2} :  } & \lstick{{q}_{1} \mapsto {2} :  } & \gate{\mathrm{U_2}\,(\mathrm{0,\pi})} & \qw & \qw\\
-	 	\nghost{{ancilla}_{0} \mapsto {3} :  } & \lstick{{ancilla}_{0} \mapsto {3} :  } & \qw & \qw & \qw\\
-	 	\nghost{{ancilla}_{1} \mapsto {4} :  } & \lstick{{ancilla}_{1} \mapsto {4} :  } & \qw & \qw & \qw\\
+	 	\nghost{{q}_{2}\;\mapsto\;{0} :  } & \lstick{{q}_{2}\;\mapsto\;{0} :  } & \qw & \qw & \qw\\
+	 	\nghost{{q}_{0}\;\mapsto\;{1} :  } & \lstick{{q}_{0}\;\mapsto\;{1} :  } & \qw & \qw & \qw\\
+	 	\nghost{{q}_{1}\;\mapsto\;{2} :  } & \lstick{{q}_{1}\;\mapsto\;{2} :  } & \gate{\mathrm{U_2}\,(\mathrm{0,\pi})} & \qw & \qw\\
+	 	\nghost{{ancilla}_{0}\;\mapsto\;{3} :  } & \lstick{{ancilla}_{0}\;\mapsto\;{3} :  } & \qw & \qw & \qw\\
+	 	\nghost{{ancilla}_{1}\;\mapsto\;{4} :  } & \lstick{{ancilla}_{1}\;\mapsto\;{4} :  } & \qw & \qw & \qw\\
 \\ }}
 \end{document}

test/python/visualization/references/test_latex_plot_barriers_false.tex

@@ -8,6 +8,6 @@
 \Qcircuit @C=1.0em @R=0.2em @!R { \\
 	 	\nghost{{q}_{0} :  } & \lstick{{q}_{0} :  } & \gate{\mathrm{H}} & \qw & \qw & \qw & \qw & \qw\\
 	 	\nghost{{q}_{1} :  } & \lstick{{q}_{1} :  } & \qw & \qw & \gate{\mathrm{H}} & \qw & \qw & \qw\\
-	 	\nghost{\mathrm{c :  }} & \lstick{\mathrm{c :  }} & \lstick{/_{_{2}}} \cw & \cw & \cw & \cw & \cw & \cw\\
+	 	\nghost{\mathrm{{c} :  }} & \lstick{\mathrm{{c} :  }} & \lstick{/_{_{2}}} \cw & \cw & \cw & \cw & \cw & \cw\\
 \\ }}
 \end{document}

test/python/visualization/references/test_latex_plot_barriers_true.tex

@@ -8,6 +8,6 @@
 \Qcircuit @C=1.0em @R=0.2em @!R { \\
 	 	\nghost{{q}_{0} :  } & \lstick{{q}_{0} :  } & \gate{\mathrm{H}} \barrier[0em]{1} & \qw & \qw \barrier[0em]{1} & \qw & \qw & \qw\\
 	 	\nghost{{q}_{1} :  } & \lstick{{q}_{1} :  } & \qw & \qw & \gate{\mathrm{H}} & \qw & \qw & \qw\\
-	 	\nghost{\mathrm{c :  }} & \lstick{\mathrm{c :  }} & \lstick{/_{_{2}}} \cw & \cw & \cw & \cw & \cw & \cw\\
+	 	\nghost{\mathrm{{c} :  }} & \lstick{\mathrm{{c} :  }} & \lstick{/_{_{2}}} \cw & \cw & \cw & \cw & \cw & \cw\\
 \\ }}
 \end{document}

test/python/visualization/references/test_latex_plot_partial_barriers.tex

@@ -8,6 +8,6 @@
 \Qcircuit @C=1.0em @R=0.2em @!R { \\
 	 	\nghost{{q}_{0} :  } & \lstick{{q}_{0} :  } & \gate{\mathrm{H}} \barrier[0em]{0} & \qw & \gate{\mathrm{H}} & \qw & \qw\\
 	 	\nghost{{q}_{1} :  } & \lstick{{q}_{1} :  } & \qw & \qw & \qw & \qw & \qw\\
-	 	\nghost{\mathrm{c :  }} & \lstick{\mathrm{c :  }} & \lstick{/_{_{2}}} \cw & \cw & \cw & \cw & \cw\\
+	 	\nghost{\mathrm{{c} :  }} & \lstick{\mathrm{{c} :  }} & \lstick{/_{_{2}}} \cw & \cw & \cw & \cw & \cw\\
 \\ }}
 \end{document}

test/python/visualization/references/test_latex_registerless_one_bit.tex

@@ -13,6 +13,6 @@
 	 	\nghost{{qry} :  } & \lstick{{qry} :  } & \qw & \qw\\
 	 	\nghost{\mathrm{{0} :  }} & \lstick{\mathrm{{0} :  }} & \cw & \cw\\
 	 	\nghost{\mathrm{{1} :  }} & \lstick{\mathrm{{1} :  }} & \cw & \cw\\
-	 	\nghost{\mathrm{crx :  }} & \lstick{\mathrm{crx :  }} & \lstick{/_{_{2}}} \cw & \cw\\
+	 	\nghost{\mathrm{{crx} :  }} & \lstick{\mathrm{{crx} :  }} & \lstick{/_{_{2}}} \cw & \cw\\
 \\ }}
 \end{document}

test/python/visualization/references/test_latex_teleport.tex

@@ -9,6 +9,6 @@
 	 	\nghost{{q}_{0} :  } & \lstick{{q}_{0} :  } & \gate{\mathrm{U}\,(\mathrm{0.3,0.2,0.1})} & \qw \barrier[0em]{2} & \qw & \ctrl{1} & \gate{\mathrm{H}} & \meter & \qw & \qw & \qw & \qw & \qw\\
 	 	\nghost{{q}_{1} :  } & \lstick{{q}_{1} :  } & \gate{\mathrm{H}} & \ctrl{1} & \qw & \targ & \meter & \qw & \qw & \qw & \qw & \qw & \qw\\
 	 	\nghost{{q}_{2} :  } & \lstick{{q}_{2} :  } & \qw & \targ & \qw & \qw & \qw & \qw & \gate{\mathrm{Z}} & \gate{\mathrm{X}} & \meter & \qw & \qw\\
-	 	\nghost{\mathrm{c :  }} & \lstick{\mathrm{c :  }} & \lstick{/_{_{3}}} \cw & \cw & \cw & \cw & \dstick{_{_{\hspace{0.0em}1}}} \cw \ar @{<=} [-2,0] & \dstick{_{_{\hspace{0.0em}0}}} \cw \ar @{<=} [-3,0] & \control \cw^(0.0){^{\mathtt{0x1}}} \cwx[-1] & \control \cw^(0.0){^{\mathtt{0x2}}} \cwx[-1] & \dstick{_{_{\hspace{0.0em}2}}} \cw \ar @{<=} [-1,0] & \cw & \cw\\
+	 	\nghost{\mathrm{{c} :  }} & \lstick{\mathrm{{c} :  }} & \lstick{/_{_{3}}} \cw & \cw & \cw & \cw & \dstick{_{_{\hspace{0.0em}1}}} \cw \ar @{<=} [-2,0] & \dstick{_{_{\hspace{0.0em}0}}} \cw \ar @{<=} [-3,0] & \control \cw^(0.0){^{\mathtt{0x1}}} \cwx[-1] & \control \cw^(0.0){^{\mathtt{0x2}}} \cwx[-1] & \dstick{_{_{\hspace{0.0em}2}}} \cw \ar @{<=} [-1,0] & \cw & \cw\\
 \\ }}
 \end{document}