fastchart examples

May 15, 2026 · View on GitHub

Each example below is a self-contained PHP script that renders the chart shown beside it. The scripts are runnable as-is with fastchart loaded; ext/gd is no longer required at runtime:

php -d extension=fastchart docs/examples/01_line_basic.php

Together the 40 scripts exercise every public method on the FastChart\* classes (105/105 covered), so this gallery doubles as live documentation: if a knob exists, an example demonstrates it.

Every script requires _bootstrap.php to resolve a TrueType font path (DejaVu on common Linux distros, Helvetica on macOS) into a $font variable, and each chart calls ->setFontPath($font) so the output is anti-aliased and portable across systems. Override with FC_FONT=/path/to/Custom.ttf if your fonts live elsewhere.

The PNGs are generated by running the scripts; modifying a script and re-running it refreshes the corresponding image.

1. Line: basic

A minimal line chart: one series, auto-scaled axes, category labels along X. renderToFile infers the format from the file extension.

(new FastChart\LineChart(640, 320))
    ->setTitle('Daily active users')
    ->setSeries([['data' => [820, 940, 870, 1020, 1180, 1250, 1340]]])
    ->setCategoryLabels(['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun'])
    ->renderToFile('01_line_basic.png');

2. Line: multi-series + smoothing

Three named series, axis titles, Catmull-Rom smoothing, circle markers, top-left legend.

(new FastChart\LineChart(640, 380))
    ->setTitle('Quarterly revenue by region')
    ->setXAxisTitle('Quarter')
    ->setYAxisTitle('Revenue ($M)')
    ->setSeries([
        ['label' => 'Americas', 'data' => [42, 51, 47, 63, 71, 78, 85, 92]],
        ['label' => 'EMEA',     'data' => [28, 33, 35, 39, 45, 52, 58, 64]],
        ['label' => 'APAC',     'data' => [18, 22, 28, 34, 41, 48, 56, 67]],
    ])
    ->setCategoryLabels(['Q1\'24','Q2\'24','Q3\'24','Q4\'24',
                         'Q1\'25','Q2\'25','Q3\'25','Q4\'25'])
    ->setLineInterpolation(FastChart\Chart::INTERP_SMOOTH)
    ->setMarkerStyle(FastChart\Chart::MARKER_CIRCLE)
    ->setLegendPosition(FastChart\Chart::LEGEND_TOP_LEFT)
    ->renderToFile('02_line_multi.png');

3. Bar: grouped (multi-series)

Side-by-side bars with custom palette, edge color, and per-bar value labels.

(new FastChart\BarChart(640, 380))
    ->setTitle('Monthly tickets opened vs closed')
    ->setSeries([
        ['label' => 'Opened', 'data' => [42, 38, 51, 47, 55, 49]],
        ['label' => 'Closed', 'data' => [35, 41, 48, 50, 52, 54]],
    ])
    ->setCategoryLabels(['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun'])
    ->setSeriesColors([0xE34A6F, 0x4FB286])
    ->setShowValues(true)
    ->setEdgeColor(0x222222)
    ->renderToFile('03_bar_grouped.png');

4. Bar: horizontal with value-axis bands

setOrientation(BAR_HORIZONTAL) swaps the axes so long category labels fit comfortably along Y. Two addVerticalBand calls highlight the SLA threshold.

(new FastChart\BarChart(680, 380))
    ->setOrientation(FastChart\BarChart::BAR_HORIZONTAL)
    ->setTitle('p95 latency by endpoint (ms)')
    ->setSeries([
        ['label' => 'Read',  'data' => [120, 85, 240, 180, 95, 310, 145]],
        ['label' => 'Write', 'data' => [180, 120, 380, 290, 140, 480, 220]],
    ])
    ->setCategoryLabels(['users', 'sessions', 'reports',
                         'search', 'auth', 'exports', 'health'])
    ->setStacked(true)
    ->addVerticalBand(0, 200, 0x4FB286, 96, 'SLA')
    ->addVerticalBand(200, 500, 0xE34A6F, 96, 'over SLA')
    ->renderToFile('04_bar_horizontal.png');

5. Pie / donut with explode

Donut hole via setDonutHoleRatio, one slice pulled out via setExplode, percentage labels rendered outside, custom palette.

(new FastChart\PieChart(560, 400))
    ->setTitle('Traffic source breakdown')
    ->setSlices([
        'Organic search' => 41, 'Direct' => 28, 'Referral' => 15,
        'Social' => 9, 'Email' => 5, 'Paid' => 2,
    ])
    ->setDonutHoleRatio(0.5)
    ->setExplode([0 => 12])
    ->setSliceLabelPosition(FastChart\Chart::LABEL_OUTSIDE)
    ->setSliceLabelFormat('%.0f%%')
    ->setSeriesColors([0x4F86C6, 0xF6AE2D, 0xE34A6F, 0x4FB286, 0x9B5DE5, 0x9D9D9D])
    ->renderToFile('05_pie_donut.png');

6. Scatter with polynomial trend line

Each point is [x, y] in data coordinates. setTrendLine(true, $color, $degree) overlays a least-squares fit; degrees 1..3 are accepted.

(new FastChart\ScatterChart(640, 400))
    ->setTitle('Page load time vs payload size')
    ->setXAxisTitle('Payload (KB)')
    ->setYAxisTitle('Time (s)')
    ->setPoints($pts)
    ->setMarkerStyle(FastChart\Chart::MARKER_CIRCLE)
    ->setMarkerSize(6)
    ->setTrendLine(true, 0xE34A6F, 2)  // quadratic fit
    ->renderToFile('06_scatter_trend.png');

7. Stock: candlestick with MA overlays + volume

setOhlcv takes rows of [timestamp, open, high, low, close, volume]. addMovingAverage accepts SMA, EMA, or WMA and any period; up to 8 overlays per chart.

(new FastChart\StockChart(800, 460))
    ->setTitle('ACME 90 day OHLCV')
    ->setOhlcv($rows)
    ->addMovingAverage(10, FastChart\StockChart::MA_SMA)
    ->addMovingAverage(20, FastChart\StockChart::MA_EMA)
    ->addMovingAverage(30, FastChart\StockChart::MA_WMA)
    ->setVolumePane(true)
    ->setCandleStyle(FastChart\Chart::STYLE_CANDLE)
    ->renderToFile('07_stock_candle_ma.png');

8. Radar / spider

Multi-series radar with shared axis labels via setCategoryLabels and a fixed scale via setMaxValue.

(new FastChart\RadarChart(560, 480))
    ->setTitle('Feature parity scorecard')
    ->setSeries([
        ['label' => 'Product A', 'data' => [8, 7, 9, 6, 8, 7]],
        ['label' => 'Product B', 'data' => [6, 9, 7, 8, 5, 9]],
    ])
    ->setCategoryLabels(['Speed', 'Reliability', 'API', 'Docs', 'Support', 'Pricing'])
    ->setMaxValue(10)
    ->setSeriesColors([0x4F86C6, 0xE34A6F])
    ->renderToFile('08_radar.png');

9. Box plot with outliers

Each box is [min, q1, median, q3, max] plus an optional outliers array. Outliers render as small open circles, capped at 128 per box.

(new FastChart\BoxPlot(640, 400))
    ->setTitle('Response time distribution by service')
    ->setYAxisTitle('Latency (ms)')
    ->setBoxes([
        ['label' => 'auth',    'min' => 18, 'q1' => 32, 'median' => 45,
         'q3' => 58, 'max' => 95,  'outliers' => [120, 135]],
        ['label' => 'search',  'min' => 80, 'q1' => 110, 'median' => 145,
         'q3' => 195, 'max' => 320, 'outliers' => [410, 480, 510]],
        // ...
    ])
    ->renderToFile('09_boxplot.png');

10. Gauge with zones

Half-circle gauge with three colored zones. setZones takes a list of {from, to, color} dicts; the needle position comes from setValue.

(new FastChart\GaugeChart(480, 320))
    ->setTitle('Server CPU utilization')
    ->setRange(0, 100)
    ->setValue(72)
    ->setZones([
        ['from' => 0,  'to' => 50,  'color' => 0x4FB286],
        ['from' => 50, 'to' => 80,  'color' => 0xF6AE2D],
        ['from' => 80, 'to' => 100, 'color' => 0xE34A6F],
    ])
    ->setValueFormat('%.0f%%')
    ->renderToFile('10_gauge.png');

11. Plot bands + line annotations

addHorizontalBand shades a Y-range region; addHorizontalLine and addVerticalLine draw dashed reference lines with optional labels.

(new FastChart\LineChart(720, 380))
    ->setTitle('Conversion rate over the deploy window')
    ->setYAxisTitle('Conversion (%)')
    ->setSeries([['data' => [3.2, 3.4, 3.1, 3.3, 3.5, 4.1, 4.4, 4.2, 4.5, 4.7, 4.6, 4.8]]])
    ->setCategoryLabels(['Wk1','Wk2','Wk3','Wk4','Wk5','Wk6',
                         'Wk7','Wk8','Wk9','Wk10','Wk11','Wk12'])
    ->addHorizontalBand(4.0, 5.0, 0x4FB286, 96, 'target')
    ->addHorizontalLine(4.5, 'goal', 0xE34A6F)
    ->addVerticalLine(5.0, 'deploy', 0x4F86C6)
    ->setMarkerStyle(FastChart\Chart::MARKER_CIRCLE)
    ->renderToFile('11_plot_bands_annotations.png');

12. Themes and gradient fills

Same data, three presentations. setTheme(THEME_LIGHT|THEME_DARK) swaps the palette. setGradientFill ramps the bar fill; setDropShadow + setShadowAlpha adds an offset shadow on the filled shapes.

(new FastChart\BarChart(420, 260))
    ->setTitle('Gradient + shadow')->setSeries($data)->setCategoryLabels($labels)
    ->setGradientFill(0x4F86C6, 0xE34A6F, FastChart\Chart::GRADIENT_VERTICAL)
    ->setDropShadow(3, 3, 0x000000)->setShadowAlpha(80)
    ->renderToFile('12c_gradient.png');

Light	Dark	Gradient + shadow

13. Secondary Y axis

A series joins the right axis by adding 'axis' => 'right' to its dict. Honored on LineChart (and any chart that plumbs range_r).

(new FastChart\LineChart(720, 380))
    ->setTitle('Traffic vs revenue (independent scales)')
    ->setSecondaryYAxis(true)
    ->setSecondaryYAxisTitle('Revenue ($K)')
    ->setSeries([
        ['label' => 'Page views', 'data' => [12000, 14500, /* … */]],
        ['label' => 'Revenue', 'axis' => 'right', 'data' => [42, 48, /* … */]],
    ])
    ->renderToFile('13_secondary_axis.png');

14. Bubble chart

Each point is [x, y, size]. Bubble area scales with the third dimension so visual weight matches magnitude.

(new FastChart\BubbleChart(640, 400))
    ->setTitle('Project size vs delivery risk')
    ->setPoints([
        [8, 2.5, 5], [13, 1.8, 8], [21, 3.2, 12], [34, 5.5, 18],
        [55, 7.2, 25], [89, 8.9, 40], /* … */
    ])
    ->renderToFile('14_bubble.png');

15. Surface heatmap and contour

Same row-major grid rendered as a heatmap (SurfaceChart) and as iso- contours at user-supplied levels (ContourChart). setColorRamp takes [low_rgb, high_rgb] and interpolates linearly.

(new FastChart\SurfaceChart(560, 320))
    ->setTitle('Surface heatmap')
    ->setGrid($grid)
    ->setColorRamp(0x1F4E79, 0xE34A6F)
    ->renderToFile('15a_surface.png');

(new FastChart\ContourChart(560, 320))
    ->setTitle('Filled contour at 7 levels')
    ->setGrid($grid)
    ->setLevels([-8, -4, -2, 0, 2, 4, 8])
    ->setFilled(true)
    ->setColorRamp(0x1F4E79, 0xE34A6F)
    ->renderToFile('15b_contour.png');

Surface	Contour

16. Polar chart

Each point is [angle_deg, radius]. Multi-series with up to 8 traces.

(new FastChart\PolarChart(520, 520))
    ->setTitle('Antenna gain pattern')
    ->setSeries([
        ['label' => 'Antenna A', 'data' => $pts_a],
        ['label' => 'Antenna B', 'data' => $pts_b],
    ])
    ->setMaxRadius(8)
    ->renderToFile('16_polar.png');

17. Gantt timeline

Tasks with [name, start, end, depends?, milestone?] shapes. Milestones render as diamonds at a single point.

(new FastChart\GanttChart(720, 380))
    ->setTitle('Q4 release timeline')
    ->setTimeRange($base, $base + 60 * 86400)
    ->setTasks([
        ['name' => 'Spec',   'start' => $base + 0  * 86400, 'end' => $base + 7  * 86400],
        ['name' => 'Design', 'start' => $base + 5  * 86400, 'end' => $base + 18 * 86400, 'depends' => [0]],
        ['name' => 'Build',  'start' => $base + 15 * 86400, 'end' => $base + 38 * 86400, 'depends' => [1]],
        ['name' => 'Launch', 'start' => $base + 50 * 86400, 'end' => $base + 50 * 86400,
         'milestone' => true, 'color' => 0xE34A6F],
    ])
    ->setShowTaskLabels(true)
    ->renderToFile('17_gantt.png');

18. Stock with indicator panes

addIndicatorPane stacks a custom data strip below the price. setMovingAverages is the bulk shortcut for several SMAs at once. setVolumeColors overrides the per-bar volume color. setDateAxisStride controls X-axis tick density.

(new FastChart\StockChart(820, 520))
    ->setTitle('ACME with RSI indicator pane')
    ->setOhlcv($rows)
    ->setMovingAverages([10, 20, 50])
    ->setVolumePane(true)
    ->setVolumeColors(array_fill(0, 60, 0x9D9D9D))
    ->addIndicatorPane('RSI(14)', $rsi, ['color' => 0x9B5DE5])
    ->setDateAxisStride(FastChart\Chart::DATE_WEEK, 2)
    ->renderToFile('18_stock_indicators.png');

19. Error bars

Each setErrorBars entry is either a single positive scalar (symmetric ±) or [lo, hi] (asymmetric). Works on LineChart and ScatterChart.

(new FastChart\LineChart(640, 360))
    ->setTitle('Measured signal with confidence interval')
    ->setSeries([['data' => [12.3, 14.1, 13.5, 15.8, 17.2, 18.9, 20.1, 19.4]]])
    ->setErrorBars([0.8, 0.7, 1.2, 0.9, [0.5, 1.5], 1.0, 0.6, 1.1])
    ->renderToFile('19a_line_errors.png');

Line errors	Scatter (asymmetric)

20. Output formats

Every way to get pixels out of a chart:

$line = (new FastChart\LineChart(400, 200))
    ->setTitle('Output formats demo')
    ->setSeries([['data' => [10, 20, 15, 25, 22, 30]]]);

$line->renderToFile('out.png');           // file, format from extension
$line->renderToFile('out.svg');           // SVG goes through the same call
$png  = $line->renderPng();               // PNG bytes
$jpg  = $line->renderJpeg(85);            // JPEG bytes (quality 1..100; default 88 via setJpegQuality)
$webp = $line->renderWebp(80);            // WebP bytes (quality 1..100)
$svg  = $line->renderSvg();               // SVG document (vector)
$frag = $line->drawSvgFragment();         // <g class="fastchart">…</g>

The bytes-returning helpers skip the encode-to-disk roundtrip and are convenient for HTTP responses, base64 data URIs, or hashing. SVG defaults to glyph-path output (SVG_TEXT_PATHS) — every text element is flattened to <path> data via FreeType so the SVG renders identically in any rasterizer. Switch to native <text> for smaller, selectable output via setSvgTextMode(FastChart\Chart::SVG_TEXT_NATIVE).

GIF and AVIF were dropped in v1.0; their render* methods raise \Error. draw($canvas) is also gone — fastchart owns the pixel buffer end-to-end through plutovg. For compositing several charts onto one image, stitch SVG fragments via drawSvgFragment() or composite the bytes returned by renderPng() in userland.

22. Axis customization

Every axis-tuning knob: log scale, fixed range, rotated labels, label stride, tick mode, format strings, axis visibility, zero shelf.

(new FastChart\LineChart(720, 380))
    ->setTitle('Log-scale revenue with rotated date labels')
    ->setSeries([['data' => [120, 240, 480, 920, /* … */]]])
    ->setCategoryLabels(['2016','2017',/* … */])
    ->setYAxisScale(FastChart\Chart::SCALE_LOG)
    ->setYAxisLabelFormat('$%.0f')
    ->setXAxisLabelAngle(45)
    ->setXLabelStride(1)
    ->setTickMode(FastChart\Chart::TICK_BOTH)
    ->setZeroShelf(true)
    ->renderToFile('22a_axis_log.png');

Log + rotated	Linear, axes hidden

23. Custom styling: colors, borders, line style

Color knobs for every painted surface: chart background, plot background, axis, grid, border, text, title, axis labels, axis titles. Plus border-side bitmask, line dash style, and edge color on filled shapes.

(new FastChart\LineChart(720, 360))
    ->setTitle('Custom palette across every painted surface')
    ->setBackgroundColor(0x1A1F2C)
    ->setPlotBackgroundColor(0x232A3D)
    ->setAxisColor(0x6E7894)
    ->setGridColor(0x363D52)
    ->setBorderColor(0x6E7894)
    ->setBorderSides(FastChart\Chart::BORDER_LEFT | FastChart\Chart::BORDER_BOTTOM)
    ->setTextColor(0xC9D1E0)
    ->setTitleColor(0xFFD166)
    ->setAxisLabelColor(0xA0AAC4)
    ->setAxisTitleColor(0xC9D1E0)
    ->setLineStyle(FastChart\Chart::LINE_DASHED)
    ->setSeriesColors([0x06D6A0, 0xFFD166, 0xEF476F])
    ->setSeries([/* … */])
    ->renderToFile('23a_custom_palette.png');

Custom palette	Narrow bars + transparent bg

24. Fonts

Per-role TTF override. setFontPath + setFontSize set the global default; setTitleFont / setAxisFont / setLabelFont override per role. setThumbnailMode(true) suppresses labels and shrinks fonts for tile-sized previews.

(new FastChart\LineChart(640, 360))
    ->setTitle('Per-role font override')
    ->setFontPath('/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf')
    ->setFontSize(11)
    ->setTitleFont('/usr/share/fonts/truetype/dejavu/DejaVuSans-Bold.ttf', 18)
    ->setLabelFont('/usr/share/fonts/truetype/dejavu/DejaVuSerif.ttf', 9)
    /* … */
    ->renderToFile('24a_font_override.png');

Custom fonts	Thumbnail mode

25. Overlays, text, icons

addOverlaySeries traces an extra polyline (or area) on top of the chart. addTextAnnotation places free-floating text at chart coordinates. addIconAt overlays an external image at a data point.

(new FastChart\LineChart(720, 380))
    ->setTitle('Daily traffic with overlay + text + icon annotations')
    ->setSeries([['label' => 'Visitors', 'data' => [/* … */]]])
    ->addOverlaySeries('line', [/* baseline values */],
                       ['color' => 0x9D9D9D, 'thickness' => 1])
    ->addTextAnnotation('campaign launch', 3, 7000, 0xE34A6F)
    ->addIconAt(3, 5200, '/tmp/star.png', 20, 20)
    ->renderToFile('25_overlays_text_icons.png');

26. Stock candle styles

Same OHLCV data rendered in every candle style fastchart supports.

STYLE_CANDLE	STYLE_BAR	STYLE_DIAMOND	STYLE_I_CAP

STYLE_HOLLOW	STYLE_VOLUME	STYLE_VECTOR

(new FastChart\StockChart(420, 240))
    ->setOhlcv($rows)
    ->setCandleStyle(FastChart\Chart::STYLE_HOLLOW)  // or STYLE_BAR / DIAMOND / etc
    ->renderToFile('26e_hollow.png');

27. Area chart: stacked vs overlay

Stacked accumulates each series on top of the running total; overlay draws each series at zero baseline with translucent fills controlled by setFillOpacity.

Stacked	Overlay

28. Bar variants: floating + layered stack

setFloating(true) interprets each entry as [min, max] and draws bars between those bounds (Gantt-style). setStackMode(STACK_LAYER) overlays translucent series at the same baseline instead of summing them. setFloating must be called before setSeries so the parser reads each entry as a tuple.

Floating bars	Layered stack

29. Pie aggregation

setOtherThreshold(percent, label?) rolls every slice below the given percentage into a single Other slice. Useful for long-tail breakdowns where dozens of < 1% slivers would crowd the legend.

Without aggregation	With Other = 2%

30. Image map for clickable charts

Scatter points carrying 'href' (and optional 'tooltip') become clickable; getImageMap('mapname') after any of the render*() methods (or renderToFile()) emits the HTML <map>. Schemes outside http(s)://, mailto:, fragment, and absolute path are silently rejected. Attribute values are HTML-escaped.

$chart = (new FastChart\ScatterChart(560, 360))
    ->setPoints([
        [1, 42, 'href' => '/dash?q=1&r=americas', 'tooltip' => 'Americas Q1'],
        [2, 51, 'href' => '/dash?q=2&r=americas', 'tooltip' => 'Americas Q2'],
        /* … */
    ]);
$chart->renderToFile('30_image_map.png');
$map = $chart->getImageMap('quarterly');
file_put_contents('chart.html', '<img src="30_image_map.png" usemap="#quarterly">' . $map);

31. Misc utility setters

The remaining catch-all knobs:

FastChart\Chart::version(): extension version (static)
setSize(w, h): change canvas size after construction
setPlotRect(x0, y0, x1, y1): pin the plot area to fixed pixel coordinates; useful for compositing two charts on one canvas
setStrict(true): TypeError on non-numeric Line/Area/Bar series cells instead of silent NaN coercion
setBoxWidth(percent): boxplot box width as a percent of slot
setBackgroundImage(path): bitmap behind the chart; PNG/JPEG only; open_basedir-checked at draw time

/* Stitch two charts side-by-side into one SVG document via
 * drawSvgFragment(). v1.0 owns the canvas end-to-end — there's no
 * shared GdImage to composite onto — so multi-chart layouts are
 * built at the SVG layer and rasterized once if needed. */
$left = (new FastChart\LineChart(380, 320))
    ->setTitle('Left chart')->setSeries([/* … */])
    ->drawSvgFragment();
$right = (new FastChart\BarChart(380, 320))
    ->setTitle('Right chart')->setSeries([/* … */])
    ->drawSvgFragment();
$svg  = '<?xml version="1.0"?><svg xmlns="http://www.w3.org/2000/svg"'
      . ' width="800" height="320" viewBox="0 0 800 320">';
$svg .= '<g transform="translate(0,0)">'    . $left  . '</g>';
$svg .= '<g transform="translate(420,0)">'  . $right . '</g>';
$svg .= '</svg>';
file_put_contents('31b_two_charts.svg', $svg);

setSize after construction	Two charts on one canvas	Background image

43. Bullet chart (Stephen Few)

FastChart\BulletChart packs a horizontal performance bar, a target tick, and qualitative background bands into one compact strip. Designed as a dashboard replacement for radial gauges.

(new FastChart\BulletChart(560, 120))
    ->setTitle('Q3 revenue vs plan')
    ->setRange(0, 120)
    ->setBands([
        ['from' =>   0, 'to' =>  60, 'color' => 0xE5E7EB],
        ['from' =>  60, 'to' =>  90, 'color' => 0xCBD5E1],
        ['from' =>  90, 'to' => 120, 'color' => 0x94A3B8],
    ])
    ->setValue(78)
    ->setTarget(95)
    ->setValueFormat('%.0fM')
    ->renderToFile('43_bullet.png');

44. Pareto chart (80/20)

FastChart\ParetoChart draws descending bars with a cumulative- percentage line overlay on a secondary axis. The line crosses 80% near the few categories that explain most of the total.

(new FastChart\ParetoChart(680, 420))
    ->setTitle('Defect categories, last quarter')
    ->setBars([
        ['label' => 'Soldering', 'value' => 142],
        ['label' => 'Plating',   'value' =>  88],
        ['label' => 'Etching',   'value' =>  61],
        ['label' => 'Drilling',  'value' =>  34],
        ['label' => 'Cutting',   'value' =>  21],
        ['label' => 'Other',     'value' =>  12],
    ])
    ->setLineColor(0xE34A6F)
    ->setShowValues(true)
    ->renderToFile('44_pareto.png');

45. Calendar heatmap

FastChart\CalendarHeatmap builds a GitHub-style day-grid: seven day-of-week rows by N week columns, each cell colored by value via a low/high RGB ramp. Pass the data as ['YYYY-MM-DD' => value, ...]. Missing days render in the palette grid color.

$data = [];
$start = strtotime('2025-05-01');
$end   = strtotime('2026-04-30');
for ($ts = $start; $ts <= $end; $ts += 86400) {
    $iso = date('Y-m-d', $ts);
    $dow = (int)date('w', $ts);
    $base = $dow >= 1 && $dow <= 5 ? 6 : 1;
    $v = max(0, $base + sin($ts / 86400 / 7) * 4);
    if ($v > 0) $data[$iso] = round($v);
}
(new FastChart\CalendarHeatmap(900, 170))
    ->setTitle('Daily commits, last 12 months')
    ->setData($data)
    ->setColorRamp(0xEBEDEF, 0x216E39)
    ->renderToFile('45_calendar_heatmap.png');

46. Sunburst chart

FastChart\SunburstChart is a nested ring donut. Each ring is one level of the hierarchy; each slice's angular span is proportional to its value. Interior nodes auto-sum their children when no explicit value is set.

(new FastChart\SunburstChart(520, 520))
    ->setTitle('Workload by team & project')
    ->setHierarchy([
        'label' => 'Eng',
        'children' => [
            ['label' => 'Backend', 'children' => [
                ['label' => 'API',     'value' => 18],
                ['label' => 'Workers', 'value' => 12],
                ['label' => 'DB',      'value' =>  9],
            ]],
            ['label' => 'Frontend', 'children' => [
                ['label' => 'Web',    'value' => 14],
                ['label' => 'Mobile', 'value' => 10],
            ]],
            ['label' => 'Infra', 'children' => [
                ['label' => 'CI',       'value' => 7],
                ['label' => 'Observ.',  'value' => 5],
                ['label' => 'Security', 'value' => 4],
            ]],
        ],
    ])
    ->renderToFile('46_sunburst.png');

47. Sankey diagram

FastChart\SankeyChart lays out multi-layer flow with bezier ribbons. Node columns come from a topological pass; ribbon widths are proportional to flow value. Links reference nodes by 0-based index into setNodes(). Multi-source-to-one-sink and any number of intermediate layers are supported — the example below is a 4-layer e-commerce flow where Mobile + Tablet both feed the Samsung brand node, while every other brand has a single source.

(new FastChart\SankeyChart(860, 540))
    ->setTitle('Store orders: category -> item -> brand')
    ->setNodes([
        ['label' => 'Online Store (621)', 'color' => 0x6C8EBF],
        ['label' => 'Furnitures (162)',   'color' => 0xD6B656],
        ['label' => 'Garments (191)',     'color' => 0x6FD6D6],
        ['label' => 'Electronics (268)',  'color' => 0xC993D6],
        ['label' => 'Desk (43)'],     ['label' => 'Sofa (73)'],
        ['label' => 'Chair (46)'],    ['label' => 'Jeans (46)'],
        ['label' => 'T-Shirt (104)'], ['label' => 'Jackets (41)'],
        ['label' => 'Mobile (39)'],   ['label' => 'Tablet (73)'],
        ['label' => 'Laptop (156)'],
        ['label' => 'Stickley (43)'], ['label' => 'IKEA (73)'],
        ['label' => 'Kartell (46)'],  ['label' => "Levi's (46)"],
        ['label' => 'H&M (104)'],     ['label' => 'Puma (41)'],
        ['label' => 'Samsung (112)'], ['label' => 'Dell (156)'],
    ])
    ->setLinks([
        /* Store -> Category */
        ['from' => 0, 'to' => 1, 'value' => 162],
        ['from' => 0, 'to' => 2, 'value' => 191],
        ['from' => 0, 'to' => 3, 'value' => 268],
        /* Category -> Items */
        ['from' => 1, 'to' => 4, 'value' =>  43],
        ['from' => 1, 'to' => 5, 'value' =>  73],
        ['from' => 1, 'to' => 6, 'value' =>  46],
        ['from' => 2, 'to' => 7, 'value' =>  46],
        ['from' => 2, 'to' => 8, 'value' => 104],
        ['from' => 2, 'to' => 9, 'value' =>  41],
        ['from' => 3, 'to' => 10, 'value' =>  39],
        ['from' => 3, 'to' => 11, 'value' =>  73],
        ['from' => 3, 'to' => 12, 'value' => 156],
        /* Items -> Brands */
        ['from' =>  4, 'to' => 13, 'value' =>  43],
        ['from' =>  5, 'to' => 14, 'value' =>  73],
        ['from' =>  6, 'to' => 15, 'value' =>  46],
        ['from' =>  7, 'to' => 16, 'value' =>  46],
        ['from' =>  8, 'to' => 17, 'value' => 104],
        ['from' =>  9, 'to' => 18, 'value' =>  41],
        ['from' => 10, 'to' => 19, 'value' =>  39],
        ['from' => 11, 'to' => 19, 'value' =>  73],
        ['from' => 12, 'to' => 20, 'value' => 156],
    ])
    ->renderToFile('47_sankey.png');

48. Marimekko (Mekko) chart

FastChart\MarimekkoChart is a stacked column where each column's width is proportional to its category total, and segment heights within each column are proportional to component values. Reads as percent-of-category and percent-of-total in one shape.

(new FastChart\MarimekkoChart(700, 480))
    ->setTitle('Revenue mix by region & product')
    ->setColumns([
        ['label' => 'NA',   'segments' => [
            ['label' => 'Hardware', 'value' => 80, 'color' => 0x2563EB],
            ['label' => 'Services', 'value' => 50, 'color' => 0x10B981],
            ['label' => 'Cloud',    'value' => 70, 'color' => 0xF59E0B],
        ]],
        ['label' => 'EMEA', 'segments' => [
            ['label' => 'Hardware', 'value' => 45, 'color' => 0x2563EB],
            ['label' => 'Services', 'value' => 35, 'color' => 0x10B981],
            ['label' => 'Cloud',    'value' => 25, 'color' => 0xF59E0B],
        ]],
        ['label' => 'APAC', 'segments' => [
            ['label' => 'Hardware', 'value' => 30, 'color' => 0x2563EB],
            ['label' => 'Services', 'value' => 15, 'color' => 0x10B981],
            ['label' => 'Cloud',    'value' => 40, 'color' => 0xF59E0B],
        ]],
    ])
    ->renderToFile('48_marimekko.png');

49. Vector chart

FastChart\VectorChart draws an arrow at each (x, y) anchor pointing in the (dx, dy) direction. Arrow length is proportional to vector magnitude relative to the field's max; setColorRamp() optionally tints arrows by magnitude.

$vecs = [];
for ($x = 0; $x <= 10; $x++) {
    for ($y = 0; $y <= 10; $y++) {
        $vecs[] = ['x' => $x, 'y' => $y,
                   'dx' => -($y - 5) * 0.3,
                   'dy' =>  ($x - 5) * 0.3];
    }
}
(new FastChart\VectorChart(560, 520))
    ->setTitle('Rotational vector field')
    ->setVectors($vecs)
    ->setColorRamp(0xDDE7FF, 0x1E3A8A)
    ->renderToFile('49_vector.png');

41. Code 128 barcode (1D)

FastChart\Code128 ships a complete ISO/IEC 15417 encoder. Three subsets (A: control + uppercase, B: full ASCII printable, C: digit pairs) auto-switch within a single payload to minimise encoded length; mod-103 checksum is appended automatically. setShowText(true) renders the human-readable payload below the bars using the auto-detected default font.

(new FastChart\Code128())
    ->setData('FASTCHART-12345')
    ->setSize(400, 100)
    ->setShowText(true)
    ->renderToFile('41a_code128_alphanumeric.png');

(new FastChart\Code128())
    ->setData('0123456789012345')   // pure digits → subset C dense
    ->setSize(360, 80)
    ->setShowText(true)
    ->renderToFile('41b_code128_numeric.png');

(new FastChart\Code128())
    ->setData('FASTCHART-12345')
    ->setSize(400, 60)
    ->setShowText(false)             // bars-only compact form
    ->renderToFile('41c_code128_compact.png');

Alphanumeric (B + tail-C)	Pure digits (subset C)	Compact (no text)

42. QR code (2D)

FastChart\QrCode wraps the vendored nayuki QR encoder (vendor/qrcodegen/, MIT). Four error-correction levels: L (~7% recovery), M (~15%, default), Q (~25%), H (~30%). Higher ECC eats codeword space and may push the encoder up a version (more modules per side, denser look), but the decoded payload survives more pixel damage. Use H for QR codes physically printed on rough surfaces or overlaid with a logo; L for QR codes embedded in clean digital pipelines.

$levels = [
    ['L', FastChart\QrCode::ECC_L, '42a_qrcode_ecc_l.png'],
    ['M', FastChart\QrCode::ECC_M, '42b_qrcode_ecc_m.png'],
    ['Q', FastChart\QrCode::ECC_Q, '42c_qrcode_ecc_q.png'],
    ['H', FastChart\QrCode::ECC_H, '42d_qrcode_ecc_h.png'],
];
foreach ($levels as [$label, $ecc, $file]) {
    (new FastChart\QrCode())
        ->setData('https://github.com/iliaal/fastchart')
        ->setSize(300, 300)
        ->setEcc($ecc)
        ->renderToFile($file);
}

ECC_L (~7%)	ECC_M (~15%)	ECC_Q (~25%)	ECC_H (~30%)

Symbol classes are render-only — there's no canvas-handoff entry. Reload the encoded bytes via imagecreatefromstring() in userland if you want to composite the symbol onto an existing image.

Common patterns

renderToFile($path) is the simple path. Format infers from the file extension (.png / .jpg / .jpeg / .webp / .svg). Use renderPng() / renderJpeg($q) / renderWebp($q) / renderSvg() when you need the raw bytes for HTTP, hashing, base64, or in-memory composition.
SVG text mode. setSvgTextMode(SVG_TEXT_PATHS) (default) emits glyphs as <path> outlines so the SVG is self-contained. SVG_TEXT_NATIVE emits <text> elements — smaller files, selectable text, but requires the consumer's renderer to support SVG text.
JPEG quality. setJpegQuality(int) sets a per-instance default (1..100, default 88) used by renderJpeg() with no args and renderToFile('*.jpg'). Per-call renderJpeg(quality) overrides.
Image maps. Scatter points carrying 'href' and optional 'tooltip' become clickable; call getImageMap('mapname') after the render to emit the HTML <map>.
Strict numeric input. setStrict(true) makes Line/Area/Bar setSeries throw TypeError on non-numeric cells. Other chart types parse best-effort.
Floating bars / setStrict / setFloating ordering. A few setters must run before setSeries so the parser knows the input shape. setFloating(true) is the most common; without it, the parser expects scalars, not [min, max] tuples.