PlottingLines/index.html at main · MartaTavera/PlottingLines · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Linear Equations: Table of Values and Graphs</title>
    <style>
        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            max-width: 1200px;
            margin: 0 auto;
            padding: 20px;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            color: #333;
        }

        .container {
            background: white;
            border-radius: 15px;
            padding: 30px;
            box-shadow: 0 10px 30px rgba(0,0,0,0.2);
        }

        h1 {
            text-align: center;
            color: #4a5568;
            margin-bottom: 10px;
            font-size: 2.2em;
        }

        .subtitle {
            text-align: center;
            color: #718096;
            margin-bottom: 30px;
            font-size: 1.1em;
        }

        .section {
            margin-bottom: 30px;
            padding: 20px;
            border-radius: 10px;
            border-left: 4px solid #667eea;
            background: #f8fafc;
        }

        .input-group {
            display: flex;
            align-items: center;
            gap: 15px;
            margin-bottom: 20px;
            flex-wrap: wrap;
        }

        label {
            font-weight: bold;
            color: #4a5568;
        }

        input[type="text"] {
            padding: 8px 12px;
            border: 2px solid #e2e8f0;
            border-radius: 6px;
            font-size: 16px;
            width: 80px;
            text-align: center;
        }

        input[type="text"]:focus {
            outline: none;
            border-color: #667eea;
        }

        .fraction-help {
            font-size: 0.9em;
            color: #718096;
            margin-top: 10px;
            background: #f7fafc;
            padding: 10px;
            border-radius: 6px;
        }

        .equation-display {
            font-size: 1.4em;
            font-weight: bold;
            color: #667eea;
            background: #edf2f7;
            padding: 15px;
            border-radius: 8px;
            text-align: center;
            margin: 20px 0;
        }

        .content-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 20px;
            margin-top: 20px;
            align-items: start;
        }

        @media (max-width: 1000px) {
            .content-grid {
                grid-template-columns: 1fr;
            }
        }

        table {
            width: 100%;
            border-collapse: collapse;
            margin: 20px 0;
            background: white;
            border-radius: 8px;
            overflow: hidden;
            box-shadow: 0 4px 6px rgba(0,0,0,0.1);
        }

        th, td {
            padding: 12px;
            text-align: center;
            border-bottom: 1px solid #e2e8f0;
        }

        th {
            background: #667eea;
            color: white;
            font-weight: bold;
        }

        .calculation {
            color: #718096;
            font-size: 0.9em;
        }

        #canvas {
            border: 2px solid #e2e8f0;
            border-radius: 8px;
            background: white;
            box-shadow: 0 4px 6px rgba(0,0,0,0.1);
        }

        .preset-buttons {
            display: flex;
            gap: 10px;
            flex-wrap: wrap;
            margin: 20px 0;
        }

        .preset-btn {
            padding: 8px 15px;
            border: none;
            border-radius: 20px;
            background: #667eea;
            color: white;
            cursor: pointer;
            font-size: 14px;
            transition: all 0.3s ease;
        }

        .preset-btn:hover {
            background: #5a67d8;
            transform: translateY(-2px);
        }

        .highlight-row {
            background: #fef5e7 !important;
            animation: highlight 0.5s ease-in-out;
        }

        @keyframes highlight {
            0% { background: #fed7d7; }
            100% { background: #fef5e7; }
        }

        .table-input {
            width: 60px;
            padding: 5px;
            border: 1px solid #e2e8f0;
            border-radius: 4px;
            text-align: center;
            font-size: 14px;
        }

        .table-input:focus {
            outline: none;
            border-color: #667eea;
            background: #f0fff4;
        }

        .add-row-btn {
            background: #48bb78;
            color: white;
            border: none;
            padding: 8px 15px;
            border-radius: 6px;
            cursor: pointer;
            font-size: 14px;
            margin: 10px 0;
            transition: background 0.3s ease;
        }

        .add-row-btn:hover {
            background: #38a169;
        }

        .remove-row {
            background: #e53e3e;
            color: white;
            border: none;
            padding: 3px 8px;
            border-radius: 4px;
            cursor: pointer;
            font-size: 12px;
            margin-left: 5px;
        }

        .remove-row:hover {
            background: #c53030;
        }

        .graph-controls {
            display: flex;
            gap: 10px;
            margin: 15px 0;
            flex-wrap: wrap;
            align-items: center;
        }

        .control-btn {
            padding: 8px 15px;
            border: none;
            border-radius: 6px;
            cursor: pointer;
            font-size: 14px;
            transition: all 0.3s ease;
        }

        .toggle-line {
            background: #667eea;
            color: white;
        }

        .toggle-line:hover {
            background: #5a67d8;
        }

        .toggle-line.active {
            background: #48bb78;
        }

        .toggle-points {
            background: #e53e3e;
            color: white;
        }

        .toggle-points:hover {
            background: #c53030;
        }

        .toggle-points.active {
            background: #38a169;
        }

        .clear-manual {
            background: #ed8936;
            color: white;
        }

        .clear-manual:hover {
            background: #dd6b20;
        }

        .graph-info {
            font-size: 12px;
            color: #718096;
            margin-top: 10px;
            background: #f7fafc;
            padding: 8px;
            border-radius: 4px;
        }

        .explanation {
            background: #e6fffa;
            padding: 15px;
            border-radius: 8px;
            margin: 15px 0;
            border-left: 4px solid #38b2ac;
        }

        .step {
            margin: 10px 0;
            padding: 10px;
            background: #f0fff4;
            border-radius: 6px;
            border-left: 3px solid #48bb78;
        }
    </style>
</head>
<body>
    <div class="container">
        <h1>📊 Linear Equations: Tables of Values & Graphs</h1>
        <p class="subtitle">GCSE Mathematics - Explore how equations become graphs!</p>

        <div class="section">
            <h3>🎯 Enter Your Linear Equation</h3>
            <div class="input-group">
                <label>y =</label>
                <input type="text" id="gradient" value="2" placeholder="e.g. 1/2 or 0.5">
                <label>x +</label>
                <input type="text" id="intercept" value="1" placeholder="e.g. 3/4 or 0.75">
            </div>

            <div class="fraction-help">
                💡 <strong>Tip:</strong> You can enter fractions (like 1/2, -2/3) or decimals (like 0.5, -0.67)
            </div>

            <div class="equation-display" id="equation">y = 2x + 1</div>

            <div class="preset-buttons">
                <button class="preset-btn" onclick="setEquation('1', '0')">y = x</button>
                <button class="preset-btn" onclick="setEquation('2', '3')">y = 2x + 3</button>
                <button class="preset-btn" onclick="setEquation('-1', '4')">y = -x + 4</button>
                <button class="preset-btn" onclick="setEquation('1/2', '-2')">y = ½x - 2</button>
                <button class="preset-btn" onclick="setEquation('-2/3', '1/4')">y = -⅔x + ¼</button>
                <button class="preset-btn" onclick="setEquation('0', '2')">y = 2</button>
            </div>
        </div>

        <div class="content-grid">
            <div class="section">
                <h3>📋 Interactive Table of Values</h3>
                <p style="color: #718096; margin-bottom: 15px;">
                    Start by adding rows and choosing your own x-values to explore!
                </p>
                <table id="valueTable">
                    <thead>
                        <tr>
                            <th>x</th>
                            <th>y</th>
                            <th>Calculation</th>
                            <th>Action</th>
                        </tr>
                    </thead>
                    <tbody id="tableBody">
                    </tbody>
                </table>

                <div style="display: flex; gap: 10px; margin: 15px 0;">
                    <button class="add-row-btn" onclick="addNewRow()">+ Add New Row</button>
                    <button class="preset-btn" onclick="addCommonValues()">📊 Add Common Values</button>
                </div>
            </div>

            <div class="section">
                <h3>📈 Interactive Graph</h3>
                <div class="graph-controls">
                    <button class="control-btn toggle-line" id="lineToggle" onclick="toggleLine()">
                        ⚪ Show Line
                    </button>
                    <button class="control-btn toggle-points active" id="pointsToggle" onclick="togglePoints()">
                        🔴 Auto Points
                    </button>
                    <button class="control-btn clear-manual" onclick="clearManualPoints()">
                        🗑️ Clear Manual Points
                    </button>
                </div>

                <canvas id="canvas" width="400" height="400" onclick="addManualPoint(event)" style="cursor: crosshair;"></canvas>

                <div class="graph-info">
                    💡 <strong>Click on the graph</strong> to add your own points!<br>
                    🔵 Blue line shows the equation | 🔴 Red dots from table | 🟢 Green dots you clicked
                </div>
            </div>
        </div>
    </div>

    <script>
        let tableData = [];
        let showLine = false;
        let showAutoPoints = true;
        let manualPoints = [];

        // Function to parse fractions and decimals
        function parseValue(input) {
            if (typeof input === 'string' && input.includes('/')) {
                const parts = input.split('/');
                if (parts.length === 2) {
                    const numerator = parseFloat(parts[0]);
                    const denominator = parseFloat(parts[1]);
                    if (!isNaN(numerator) && !isNaN(denominator) && denominator !== 0) {
                        return numerator / denominator;
                    }
                }
            }
            return parseFloat(input) || 0;
        }

        function updateXValue(index, newValue) {
            tableData[index] = newValue;
            updateTableRow(index);
            drawGraph();
        }

        function updateTableRow(index) {
            const m = parseValue(document.getElementById('gradient').value);
            const c = parseValue(document.getElementById('intercept').value);
            const x = tableData[index];

            const row = document.getElementById('tableBody').children[index];
            const yCell = row.cells[1];
            const calcCell = row.cells[2];

            // Only update if x has a valid value
            if (x !== '' && !isNaN(parseValue(x))) {
                const xVal = parseValue(x);
                const y = m * xVal + c;

                let calculation;
                if (m === 0) {
                    calculation = `${c}`;
                } else if (c === 0) {
                    calculation = `${m} × ${xVal} = ${(m * xVal).toFixed(1)}`;
                } else {
                    const mx = m * xVal;
                    if (c >= 0) {
                        calculation = `${m} × ${xVal} + ${c} = ${mx.toFixed(1)} + ${c} = ${y.toFixed(1)}`;
                    } else {
                        calculation = `${m} × ${xVal} - ${Math.abs(c)} = ${mx.toFixed(1)} - ${Math.abs(c)} = ${y.toFixed(1)}`;
                    }
                }

                yCell.textContent = y.toFixed(1);
                calcCell.innerHTML = `<span class="calculation">${calculation}</span>`;

                row.classList.add('highlight-row');
                setTimeout(() => row.classList.remove('highlight-row'), 500);
            } else {
                // Empty or invalid input
                yCell.textContent = '-';
                calcCell.innerHTML = `<span class="calculation" style="color: #a0aec0;">Enter x-value above</span>`;
            }
        }

        function addNewRow() {
            tableData.push(''); // Add empty value
            generateTable();
            // Focus on the new input field
            setTimeout(() => {
                const newInputs = document.querySelectorAll('.table-input');
                const lastInput = newInputs[newInputs.length - 1];
                if (lastInput) {
                    lastInput.focus();
                    lastInput.select();
                }
            }, 100);
        }

        function removeRow(index) {
            tableData.splice(index, 1);
            generateTable();
            drawGraph();
        }

        function toggleLine() {
            showLine = !showLine;
            const btn = document.getElementById('lineToggle');
            if (showLine) {
                btn.textContent = '🔵 Hide Line';
                btn.classList.add('active');
            } else {
                btn.textContent = '⚪ Show Line';
                btn.classList.remove('active');
            }
            drawGraph();
        }

        function togglePoints() {
            showAutoPoints = !showAutoPoints;
            const btn = document.getElementById('pointsToggle');
            if (showAutoPoints) {
                btn.textContent = '🔴 Auto Points';
                btn.classList.add('active');
            } else {
                btn.textContent = '⚪ Hide Auto Points';
                btn.classList.remove('active');
            }
            drawGraph();
        }

        function clearManualPoints() {
            manualPoints = [];
            drawGraph();
        }

        function addManualPoint(event) {
            const canvas = document.getElementById('canvas');
            const rect = canvas.getBoundingClientRect();
            const x = event.clientX - rect.left;
            const y = event.clientY - rect.top;

            // Convert pixel coordinates to graph coordinates
            const centerX = canvas.width / 2;
            const centerY = canvas.height / 2;
            const scale = 30;

            const graphX = (x - centerX) / scale;
            const graphY = -(y - centerY) / scale;

            manualPoints.push({x: graphX, y: graphY});
            drawGraph();
        }

        function updateEquation() {
            const mInput = document.getElementById('gradient').value;
            const cInput = document.getElementById('intercept').value;
            const m = parseValue(mInput);
            const c = parseValue(cInput);

            let equationText = 'y = ';
            if (m === 0) {
                equationText += c;
            } else if (m === 1) {
                equationText += c >= 0 ? `x + ${c}` : `x - ${Math.abs(c)}`;
            } else if (m === -1) {
                equationText += c >= 0 ? `-x + ${c}` : `-x - ${Math.abs(c)}`;
            } else {
                // Display original input if it's a fraction, otherwise show decimal
                const mDisplay = mInput.includes('/') ? mInput : m;
                const cDisplay = cInput.includes('/') ? cInput : c;

                if (c >= 0) {
                    equationText += `${mDisplay}x + ${cDisplay}`;
                } else {
                    equationText += `${mDisplay}x - ${Math.abs(cDisplay)}`;
                }
            }

            document.getElementById('equation').textContent = equationText;
            generateTable();
            drawGraph();
        }

        function setEquation(m, c) {
            document.getElementById('gradient').value = m;
            document.getElementById('intercept').value = c;
            updateEquation();
        }

        function generateTable() {
            const mInput = document.getElementById('gradient').value;
            const cInput = document.getElementById('intercept').value;
            const m = parseValue(mInput);
            const c = parseValue(cInput);
            const tableBody = document.getElementById('tableBody');

            tableBody.innerHTML = '';

            // If table is empty, show a helpful message
            if (tableData.length === 0) {
                const row = tableBody.insertRow();
                const cell = row.insertCell(0);
                cell.colSpan = 4;
                cell.style.textAlign = 'center';
                cell.style.padding = '20px';
                cell.style.color = '#718096';
                cell.innerHTML = '📝 Click "Add New Row" to start building your table of values!';
                return;
            }

            tableData.forEach((x, index) => {
                const row = tableBody.insertRow();

                const xCell = row.insertCell(0);
                const yCell = row.insertCell(1);
                const calcCell = row.insertCell(2);
                const actionCell = row.insertCell(3);

                // Make x-value editable
                const inputValue = x === '' ? '' : x;
                xCell.innerHTML = `<input type="text" class="table-input" value="${inputValue}" onchange="updateXValue(${index}, this.value)" onblur="updateXValue(${index}, this.value)" placeholder="Enter x">`;

                // Only calculate if x has a value
                if (x !== '' && !isNaN(parseValue(x))) {
                    const xVal = parseValue(x);
                    const y = m * xVal + c;

                    let calculation;
                    if (m === 0) {
                        calculation = `${c}`;
                    } else if (c === 0) {
                        calculation = `${m} × ${xVal} = ${(m * xVal).toFixed(1)}`;
                    } else {
                        const mx = m * xVal;
                        if (c >= 0) {
                            calculation = `${m} × ${xVal} + ${c} = ${mx.toFixed(1)} + ${c} = ${y.toFixed(1)}`;
                        } else {
                            calculation = `${m} × ${xVal} - ${Math.abs(c)} = ${mx.toFixed(1)} - ${Math.abs(c)} = ${y.toFixed(1)}`;
                        }
                    }

                    yCell.textContent = y.toFixed(1);
                    calcCell.innerHTML = `<span class="calculation">${calculation}</span>`;
                } else {
                    // Empty row waiting for input
                    yCell.textContent = '-';
                    calcCell.innerHTML = `<span class="calculation" style="color: #a0aec0;">Enter x-value above</span>`;
                }

                // Add remove button
                actionCell.innerHTML = `<button class="remove-row" onclick="removeRow(${index})">×</button>`;

                // Animate row appearance
                row.style.opacity = '0.3';
                setTimeout(() => {
                    row.style.opacity = '1';
                    if (x !== '' && !isNaN(parseValue(x))) {
                        row.classList.add('highlight-row');
                        setTimeout(() => row.classList.remove('highlight-row'), 500);
                    }
                }, index * 50);
            });
        }

        function addCommonValues() {
            tableData = [-2, -1, 0, 1, 2];
            generateTable();
            drawGraph();
        }

        function drawGraph() {
            const canvas = document.getElementById('canvas');
            const ctx = canvas.getContext('2d');
            const width = canvas.width;
            const height = canvas.height;

            // Clear canvas
            ctx.clearRect(0, 0, width, height);

            // Set up coordinate system
            const centerX = width / 2;
            const centerY = height / 2;
            const scale = 30;

            // Draw grid
            ctx.strokeStyle = '#e2e8f0';
            ctx.lineWidth = 1;

            for (let i = -10; i <= 10; i++) {
                // Vertical lines
                ctx.beginPath();
                ctx.moveTo(centerX + i * scale, 0);
                ctx.lineTo(centerX + i * scale, height);
                ctx.stroke();

                // Horizontal lines
                ctx.beginPath();
                ctx.moveTo(0, centerY + i * scale);
                ctx.lineTo(width, centerY + i * scale);
                ctx.stroke();
            }

            // Draw axes
            ctx.strokeStyle = '#4a5568';
            ctx.lineWidth = 2;

            // X-axis
            ctx.beginPath();
            ctx.moveTo(0, centerY);
            ctx.lineTo(width, centerY);
            ctx.stroke();

            // Y-axis
            ctx.beginPath();
            ctx.moveTo(centerX, 0);
            ctx.lineTo(centerX, height);
            ctx.stroke();

            // Draw axis labels
            ctx.fillStyle = '#4a5568';
            ctx.font = '12px Arial';
            ctx.textAlign = 'center';

            for (let i = -6; i <= 6; i++) {
                if (i !== 0) {
                    ctx.fillText(i.toString(), centerX + i * scale, centerY + 15);
                    ctx.fillText((-i).toString(), centerX - 15, centerY + i * scale);
                }
            }

            // Get equation parameters
            const m = parseValue(document.getElementById('gradient').value);
            const c = parseValue(document.getElementById('intercept').value);

            // Draw the line (if enabled)
            if (showLine) {
                ctx.strokeStyle = '#667eea';
                ctx.lineWidth = 3;
                ctx.beginPath();

                const startX = -8;
                const endX = 8;
                const startY = m * startX + c;
                const endY = m * endX + c;

                ctx.moveTo(centerX + startX * scale, centerY - startY * scale);
                ctx.lineTo(centerX + endX * scale, centerY - endY * scale);
                ctx.stroke();
            }

            // Draw points from table (if enabled)
            if (showAutoPoints) {
                ctx.fillStyle = '#e53e3e';

                tableData.forEach((x, index) => {
                    // Only draw points for valid x values
                    if (x !== '' && !isNaN(parseValue(x))) {
                        const xVal = parseValue(x);
                        const y = m * xVal + c;
                        const pixelX = centerX + xVal * scale;
                        const pixelY = centerY - y * scale;

                        if (pixelX >= 0 && pixelX <= width && pixelY >= 0 && pixelY <= height) {
                            ctx.beginPath();
                            ctx.arc(pixelX, pixelY, 5, 0, 2 * Math.PI);
                            ctx.fill();

                            // Add coordinate label for table points
                            ctx.fillStyle = '#2d3748';
                            ctx.font = '10px Arial';
                            ctx.fillText(`(${xVal}, ${y.toFixed(1)})`, pixelX + 8, pixelY - 8);
                            ctx.fillStyle = '#e53e3e';
                        }
                    }
                });
            }

            // Draw manual points
            ctx.fillStyle = '#48bb78';
            manualPoints.forEach((point, index) => {
                const pixelX = centerX + point.x * scale;
                const pixelY = centerY - point.y * scale;

                ctx.beginPath();
                ctx.arc(pixelX, pixelY, 6, 0, 2 * Math.PI);
                ctx.fill();

                // Add coordinate label for manual points
                ctx.fillStyle = '#2d3748';
                ctx.font = '10px Arial';
                ctx.fillText(`(${point.x.toFixed(1)}, ${point.y.toFixed(1)})`, pixelX + 8, pixelY + 15);
                ctx.fillStyle = '#48bb78';

                // Check if point is close to the line
                const expectedY = m * point.x + c;
                const tolerance = 0.3;
                if (Math.abs(point.y - expectedY) < tolerance) {
                    // Draw a small checkmark or highlight for points on the line
                    ctx.strokeStyle = '#48bb78';
                    ctx.lineWidth = 2;
                    ctx.beginPath();
                    ctx.arc(pixelX, pixelY, 10, 0, 2 * Math.PI);
                    ctx.stroke();
                }
            });
        }

        // Event listeners
        document.getElementById('gradient').addEventListener('input', updateEquation);
        document.getElementById('intercept').addEventListener('input', updateEquation);

        // Initialize
        updateEquation();
    </script>
</body>
</html>