Merge pull request #19 from qutech/hotfix/documentation

Small fixes to documentation
qutech · Apr 7, 2020 · c25d04a · c25d04a
2 parents 7fddd61 + 1aad051
commit c25d04a
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diff --git a/doc/source/examples/calculating_error_transfer_matrices.ipynb b/doc/source/examples/calculating_error_transfer_matrices.ipynb
diff --git a/doc/source/examples/extending_pulses.ipynb b/doc/source/examples/extending_pulses.ipynb
@@ -112,7 +112,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "and the extend pulse has the following control and noise operators:"
+    "and the extended pulse has the following control and noise operators:"
    ]
   },
   {

diff --git a/doc/source/examples/getting_started.ipynb b/doc/source/examples/getting_started.ipynb
@@ -34,8 +34,8 @@
     "The `PulseSequence` class requires three positional arguments at instantiation; `H_c`, `H_n`, and `dt`, with `dt` the time-deltas of piece-wise constant control. The former two represent the control and noise Hamiltonians and are passed in the same nested-list-of-lists structure of operators and coefficient lists similar to that required by [QuTiP](http://qutip.org/) (the difference being that QuTiP requires implicit functions for calculating the coefficients instead of explicit values). Optionally, we pass unique identifiers for each operator as a third element of the list. That is, \n",
     "\n",
     "```python\n",
-    "    H = [[oper1, coeff1, identifier1],\n",
-    "         [oper2, coeff2, identifier2], ...]\n",
+    "    H = [[oper1, coeffs1, identifier1],\n",
+    "         [oper2, coeffs2, identifier2], ...]\n",
     "```\n",
     "\n",
     "The filter function can then be calculated by calling the `get_filter_function` method of the `PulseSequence` instance with a list of frequencies.\n"
@@ -77,8 +77,8 @@
     "\n",
     "# Control Hamiltonian\n",
     "H_c = [\n",
-    "    [X/2, [0], 'X'],    # We don't apply any control\n",
-    "    [Z/2, [4*np.pi], 'Z'] # Qubit splitting, hbar == 1\n",
+    "    [X/2, [0], 'X'],       # We don't apply any control\n",
+    "    [Z/2, [4*np.pi], 'Z']  # Qubit splitting, hbar == 1\n",
     "]\n",
     "\n",
     "# Noise Hamiltonian\n",
@@ -135,7 +135,8 @@
     "# Plot the filter function.\n",
     "fig, ax, legend = ff.plot_filter_function(FID, omega)\n",
     "# Plot the analytic solution into the same plot\n",
-    "ax.plot(omega*tau, analytic.FID(omega*tau)/omega**2, 'x', label='Analytical')\n",
+    "ax.plot(omega*tau, analytic.FID(omega*tau)/omega**2,\n",
+    "        'x-', label='Analytical', zorder=0)\n",
     "# Update legend\n",
     "legend = ax.legend()"
    ]
@@ -234,13 +235,14 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "omega = ff.util.get_sample_frequencies(SE, n_samples=200, spacing='log',\n",
+    "omega = ff.util.get_sample_frequencies(SE, n_samples=400, spacing='log',\n",
     "                                       symmetric=False)\n",
     "# Plot the filter function\n",
-    "fig, ax, legend = ff.plot_filter_function(SE, omega)\n",
+    "fig, ax, legend = ff.plot_filter_function(SE, omega, yscale='log')\n",
+    "ax.set_ylim(bottom=1e-13)\n",
     "# Plot the analytical solution\n",
-    "ax.plot(omega*tau, analytic.SE(omega*tau)/omega**2, 'x',\n",
-    "        label='Analytical (Bang-Bang)')\n",
+    "ax.plot(omega*tau, analytic.SE(omega*tau)/omega**2, '--',\n",
+    "        label='Analytical (Bang-Bang)', zorder=0)\n",
     "legend = ax.legend()\n",
     "\n",
     "ff.plot_bloch_vector_evolution(SE, psi0=psi_i, n_samples=101, figsize=(4, 4))"
@@ -250,7 +252,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "The discrepancy to the analytical solution is due to the finite pulse width we have chosen here. We can see that, contrary to the FID-like filter function along $\\sigma_x$, the dephasing filter function of the SE pulse drops to (almost) zero for DC noise, affirming that indeed the pulse enhances coherence as it filters out frequencies slower than the pulse duration."
+    "The discrepancy to the analytical solution is due to the finite pulse width we have chosen here. We can see that, contrary to the FID-like filter function along $\\sigma_x$, the dephasing filter function of the SE pulse drops to (almost) zero for DC noise, affirming that indeed the pulse cancels dephasing as it filters out noise frequencies slower than the pulse duration."
    ]
   }
  ],
@@ -274,5 +276,5 @@
   }
  },
  "nbformat": 4,
- "nbformat_minor": 2
+ "nbformat_minor": 4
 }
diff --git a/doc/source/examples/periodic_driving.ipynb b/doc/source/examples/periodic_driving.ipynb
diff --git a/doc/source/examples/quantum_fourier_transform.ipynb b/doc/source/examples/quantum_fourier_transform.ipynb
diff --git a/doc/source/examples/qutip_integration.ipynb b/doc/source/examples/qutip_integration.ipynb
@@ -118,7 +118,7 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "Evidently, the pulses with linear and random initial amplitudes filter out DC noise better than those with sinusoidal initial amplitudes, in particular for $\\sigma_y$ noise on the first qubit. There, they they acquire a DCG-like character to an extent."
+    "Evidently, the pulses with linear and random initial amplitudes filter out DC noise better than those with sinusoidal initial amplitudes, in particular for $\\sigma_y$ noise on the first qubit. There, the filter function has DCG-like character to an extent."
    ]
   }
  ],

diff --git a/filter_functions/pulse_sequence.py b/filter_functions/pulse_sequence.py
@@ -1356,8 +1356,8 @@ def concatenate(pulses: Iterable[PulseSequence],
         calculation of the composite filter function is forced.
     calc_pulse_correlation_ff : bool, optional
         Switch to control whether the pulse correlation filter function (see
-        :ref:`notes`) is calculated. If *omega* is not given, the cached
-        frequencies of all *pulses* need to be equal.
+        :ref:`Notes <notes>`) is calculated. If *omega* is not given, the
+        cached frequencies of all *pulses* need to be equal.
     calc_filter_function : bool, optional
         Switch to force the calculation of the filter function to be carried
         out or not. Overrides the automatic behavior of calculating it if at
@@ -1384,8 +1384,10 @@ def concatenate(pulses: Iterable[PulseSequence],
     .. math::
 
         F_{\alpha\beta}^{(gg')}(\omega) = e^{i\omega(t_{g-1} - t_{g'-1})}
-            \mathcal{R}^{(g)}(\omega)\mathcal{Q}^{(g-1)}
-            \mathcal{Q}^{(g'-1)\dagger}\mathcal{R}^{(g')\dagger}(\omega),
+            \left[\mathcal{Q}^{(g'-1)\dagger}
+                  \mathcal{R}^{(g')\dagger}(\omega)\right]_{k\alpha}
+            \left[\mathcal{R}^{(g)}(\omega)
+                  \mathcal{Q}^{(g-1)}\right]_{\beta l},
 
     where :math:`g,g'` index the pulse in the sequence and :math:`\alpha,\beta`
     index the noise operators.