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6 <title>Double pendulum</title>
7 <style>
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104 </style>
105 </head>
106 <body>
107 <main>
108 <header>
109 <h1>Double pendulum</h1>
110 <p class="sub">Raise the energy and listen for where the motion becomes chaotic.</p>
111 </header>
113 <div class="grid">
114 <section class="card">
115 <canvas id="canvas"></canvas>
116 <form id="controls" class="row">
117 <span class="label">Energy</span>
118 <input id="energy" type="range" value="50" min="0" max="120" step="0.1" aria-label="Energy" />
119 <span id="energy-value" class="num">50.0 J</span>
120 <button type="submit" class="primary" title="Start from hanging rest with this energy">Strike</button>
121 <button type="button" id="pause" disabled>Pause</button>
122 </form>
123 <div id="ghost-row" class="row">
124 <label class="chip" title="A second pendulum started with the outer arm offset by a tiny angle"><input id="ghost-toggle" type="checkbox" /><span>Ghost</span></label>
125 <span id="ghost-controls" class="row" hidden>
126 <span class="label">Offset</span>
127 <input id="ghost-offset" type="range" min="-12" max="-1" step="1" value="-10" aria-label="Ghost offset (power of ten)" />
128 <span id="ghost-offset-value" class="num"></span>
129 <button id="ghost-reset" type="button" title="Restart the ghost from the pendulum's current state">Reset</button>
130 </span>
131 <span id="ghost-sep" class="num muted"></span>
132 </div>
133 <details>
134 <summary>Parameters</summary>
135 <form id="param-form">
136 <label><span>m<sub>1</sub></span> <input id="p-m1" type="number" step="any" /> <span class="unit">kg</span></label>
137 <label><span>m<sub>2</sub></span> <input id="p-m2" type="number" step="any" /> <span class="unit">kg</span></label>
138 <label><span>l<sub>1</sub></span> <input id="p-l1" type="number" step="any" /> <span class="unit">m</span></label>
139 <label><span>l<sub>2</sub></span> <input id="p-l2" type="number" step="any" /> <span class="unit">m</span></label>
140 <label><span>g</span> <input id="p-g" type="number" step="any" /> <span class="unit">m/s²</span></label>
141 <label title="Amplitude decay time from drag on the bobs (all modes). 0 = no damping."><span>τ</span> <input id="p-tau" type="number" step="any" min="0" /> <span class="unit">s decay</span></label>
142 </form>
143 <div id="param-actions" class="row">
144 <button type="submit" form="param-form">Apply</button>
145 <label class="muted">Preset <select id="preset">
146 <option value="">custom</option>
147 <option value="equal">l2 = 1 m</option>
148 <option value="tenth">l2 = 1.5667 m</option>
149 <option value="golden">l2 = 2 m</option>
150 <option value="eightThirds">l2 = 2.1637 m</option>
151 <option value="twelfth">l2 = 3.2476 m</option>
152 <option value="doubleOctave">l2 = 6.886 m</option>
153 </select></label>
154 <span id="param-status"></span>
155 </div>
156 <div id="params"></div>
157 </details>
158 </section>
160 <section class="card">
161 <div class="chips" id="toggles">
162 <label class="chip"><input id="spec-toggle" type="checkbox" /><span>Spectrogram</span></label>
163 </div>
164 <p id="plots-empty" class="muted">Choose what to plot.</p>
165 <figure id="spec-fig" hidden>
166 <div id="spectrogram"></div>
167 <figcaption id="spec-label" class="muted"></figcaption>
168 </figure>
169 <div id="traces"></div>
170 </section>
171 </div>
173 <section class="card" id="audio">
174 <div class="row">
175 <button id="sound" type="button" class="sound" title="With sound on, every Strike plays a note">Sound off</button>
176 <label><span class="label">Sound of</span> <select id="signal"></select></label>
177 <label><span class="label">Volume</span> <input id="volume" type="range" min="0" max="1" step="0.01" value="0.5" /></label>
178 <span id="audio-chips" class="chips">
179 <label class="chip"><input id="audio-spec-toggle" type="checkbox" /><span>Spectrogram</span></label>
180 </span>
181 </div>
182 <div class="row">
183 <label class="grow"><span class="label">Pitch</span> <input id="pitch" type="range" min="0" max="1000" step="1" aria-label="Pitch of the lower mode" /></label>
184 <span id="pitch-value" class="num"></span>
185 </div>
186 <div class="row"><span id="audio-status" class="muted"></span></div>
187 <figure id="audio-spec-fig" hidden>
188 <div id="audio-spectrogram"></div>
189 <figcaption id="audio-spec-label" class="muted"></figcaption>
190 </figure>
191 <div id="audio-traces"></div>
192 </section>
193 </main>
194 <script type="module" src="/src/main.ts"></script>
195 </body>
196</html>