feat: Ch04 Quantization Noise

Change-Id: Ie5b7d15f9b222b4ef4148c611b434a47e0dcb4de
diff --git a/dcs/frames/__init__.py b/dcs/frames/__init__.py
index f365349..1172ee0 100644
--- a/dcs/frames/__init__.py
+++ b/dcs/frames/__init__.py
@@ -14,6 +14,7 @@
 from .ch03_psd import Ch03PsdWindow
 from .ch04_sampling import Ch04SamplingWindow
 from .ch04_window import Ch04WindowWindow
+from .ch04_quantization_noise import Ch04QuantizationNoiseWindow
 
 
 def get_windows() -> List[Type[base.Window]]:
@@ -25,6 +26,7 @@
         Ch03PsdWindow,
         Ch04SamplingWindow,
         Ch04WindowWindow,
+        Ch04QuantizationNoiseWindow,
     ]
 
 
diff --git a/dcs/frames/ch04_quantization_noise.py b/dcs/frames/ch04_quantization_noise.py
new file mode 100644
index 0000000..faa32f5
--- /dev/null
+++ b/dcs/frames/ch04_quantization_noise.py
@@ -0,0 +1,156 @@
+#  SPDX-License-Identifier: MPL-2.0
+#    Copyright (c) 2022 Philipp Le <philipp@philipple.de>.
+#  This Source Code Form is subject to the terms of the Mozilla Public
+#  License, v. 2.0. If a copy of the MPL was not distributed with this
+#  file, You can obtain one at https://mozilla.org/MPL/2.0/.
+
+from __future__ import annotations
+
+from tkinter import ttk, LEFT, BOTH
+from pydantic import confloat, conint
+from dcs.config import default_store, ConfigObject, ui_create, ConfigControlFrame
+import numpy as np
+import scipy.signal.windows
+from dcs.frames.base import BaseFrame, Window
+from dcs.frames.groups import Ch04Group
+from dcs.utils import swap_freq, abs_log_fft
+
+import matplotlib
+matplotlib.use('TkAgg')
+from matplotlib.figure import Figure
+from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg
+
+
+@ui_create
+class ConfigCh04QuantizationNoise(ConfigObject):
+    _KEY = 'ch04_quantization_noise'
+
+    freq: confloat(ge=0.0, lt=128.0, multiple_of=1.0) = 10.0
+    amplitude: confloat(ge=0.0, lt=10.0, multiple_of=0.01) = 5.0
+
+    adc_bits: conint(ge=1, lt=25) = 8
+    adc_min: confloat(ge=-50.0, lt=0.0, multiple_of=0.1) = -5.0
+    adc_max: confloat(ge=0.0, lt=50.0, multiple_of=0.1) = 5.0
+
+    def make_config_widget(self, parent: ttk.Widget) -> ConfigControlFrame:
+        frm = ConfigControlFrame(parent, borderwidth=1, relief='raised')
+
+        frm1 = ttk.Frame(frm, borderwidth=1, relief='raised')
+        frm1.pack()
+
+        ttk.Label(frm1, text='Signal Frequency:').grid(row=0, column=0)
+        w = self.ui_create_freq(frm1)
+        frm.add_widget(w)
+        w.grid(row=0, column=1)
+
+        ttk.Label(frm1, text='Signal Amplitude:').grid(row=1, column=0)
+        w = self.ui_create_amplitude(frm1)
+        frm.add_widget(w)
+        w.grid(row=1, column=1)
+
+        frm2 = ttk.Frame(frm, borderwidth=1, relief='raised')
+        frm2.pack()
+
+        ttk.Label(frm2, text='ADC Bits:').grid(row=0, column=0)
+        w = self.ui_create_adc_bits(frm2)
+        frm.add_widget(w)
+        w.grid(row=0, column=1)
+
+        ttk.Label(frm2, text='ADC Min. Cut-off:').grid(row=1, column=0)
+        w = self.ui_create_adc_min(frm2)
+        frm.add_widget(w)
+        w.grid(row=1, column=1)
+
+        ttk.Label(frm2, text='ADC Max. Cut-off:').grid(row=2, column=0)
+        w = self.ui_create_adc_max(frm2)
+        frm.add_widget(w)
+        w.grid(row=2, column=1)
+
+        return frm
+
+    def calc_signal(self, t: np.ndarray) -> np.ndarray:
+        center_volt = (self.adc_max + self.adc_min) / 2
+        step = (self.adc_max - self.adc_min) / np.power(2, self.adc_bits)
+        volt = np.real(center_volt + (self.amplitude * np.exp(1j * 2 * np.pi * self.freq * t)))
+        discrete = np.round(volt / step) + np.power(2, self.adc_bits - 1)
+        discrete = np.where(discrete < 0, 0, discrete)
+        upper_limit = np.power(2, self.adc_bits) - 1
+        discrete = np.where(discrete > upper_limit, upper_limit, discrete)
+        return discrete
+
+
+class Ch04QuantizationNoiseFrame(BaseFrame):
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+        self._config: ConfigCh04QuantizationNoise = default_store().get_config(ConfigCh04QuantizationNoise)
+
+        ctrl_frm = self._create_control()
+        ctrl_frm.pack(side=LEFT)
+
+        signal_frm = self._create_signal_canvas()
+        signal_frm.pack(expand=True, fill=BOTH)
+
+    def _create_control(self) -> ConfigControlFrame:
+        frm: ConfigControlFrame = self._config.make_config_widget(self)
+        frm.widgets_on_change(self._on_change)
+        return frm
+
+    def _on_change(self, _, __, ___):
+        default_store().save()
+        self.draw_signal()
+
+    def _create_signal_canvas(self) -> ttk.Widget:
+        frm = ttk.Frame(self)
+
+        self._signal_fig = Figure(figsize=(12, 6), dpi=100)
+
+        self._signal_canvas = FigureCanvasTkAgg(self._signal_fig, frm)
+        self._signal_canvas.get_tk_widget().pack(expand=True, fill=BOTH)
+
+        self.draw_signal()
+
+        return frm
+
+    def draw_signal(self):
+        LENGTH = 2048
+
+        self._signal_fig.clear()
+        ax_td = self._signal_fig.add_subplot(2, 1, 1)
+        ax_td.set_xlim(0.0, 1.0)
+        ax_td.set_xlabel('time')
+        ax_td.set_ylabel('value')
+        ax_td.set_title('Time Domain')
+        ax_fd = self._signal_fig.add_subplot(2, 1, 2)
+        ax_fd.set_xlim(0, int(LENGTH/4))
+        ax_fd.set_ylim(-180, 0)
+        ax_fd.set_xlabel('frequency')
+        ax_fd.set_ylabel('value (logarithmic)')
+        ax_fd.set_title('Frequency Domain')
+
+        t = np.arange(0, LENGTH, 1) / LENGTH
+        f = swap_freq(np.fft.fftfreq(t.shape[-1], 1.0/LENGTH))
+
+        sig_td = self._config.calc_signal(t)
+        sig_td_norm = 2 * np.sqrt(2) * ((sig_td / np.power(2, self._config.adc_bits)) - 0.5)
+        sig_fd = abs_log_fft(sig_td_norm * scipy.signal.windows.blackman(len(t)))
+
+        ax_td.plot(t, sig_td, label='Quantized Signal', linestyle='solid', color='blue', linewidth=1)
+        ax_td.legend()
+
+        ax_fd.plot(f, sig_fd, label='Quantized Signal', linestyle='solid', color='blue', linewidth=1)
+        ax_fd.legend()
+
+        self._signal_fig.tight_layout()
+        self._signal_canvas.draw()
+
+
+class Ch04QuantizationNoiseWindow(Window):
+    GROUP = Ch04Group
+    TITLE = 'Quantization Noise'
+    FRAME = Ch04QuantizationNoiseFrame
+
+
+if __name__ == '__main__':
+    Ch04QuantizationNoiseWindow.main()
+