### InstallFont Example

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/05-fonts-and-themes.md

Example of how to install a custom font.

```go
fontData, _ := ioutil.ReadFile("Arial.ttf")
err := charts.InstallFont("Arial", fontData)
if err != nil {
    return err
}
```

--------------------------------

### Style Configuration Example

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/05-fonts-and-themes.md

Example of how to configure Style fields.

```go
style := charts.Style{
    FontSize:     12,
    FontColor:    charts.Color{R: 0, G: 0, B: 0, A: 255},
    StrokeColor:  charts.Color{R: 200, G: 0, B: 0, A: 255},
    StrokeWidth:  2,
}
```

--------------------------------

### NewTheme Example

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/05-fonts-and-themes.md

Example of creating a new theme.

```go
theme := charts.NewTheme(charts.ThemeDark)
```

--------------------------------

### Custom Font Configuration

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/08-usage-patterns-and-examples.md

Shows how to install a custom font and then use it in a chart.

```go
// Install custom font
fontData, _ := ioutil.ReadFile("myfont.ttf")
charts.InstallFont("MyFont", fontData)

// Use in chart
p, err := charts.LineRender(
    values,
    charts.FontFamilyOptionFunc("MyFont"),
)
```

--------------------------------

### SetDefaultFont Example

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/05-fonts-and-themes.md

Example of how to set the default font.

```go
font, _ := charts.GetFont("Arial")
charts.SetDefaultFont(font)
```

--------------------------------

### GetDefaultFont Example

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/05-fonts-and-themes.md

Example of how to get the default font.

```go
font, _ := charts.GetDefaultFont()
```

--------------------------------

### Theme Application Example

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/05-fonts-and-themes.md

Example demonstrating full theme control at the chart level.

```go
p, err := charts.LineRender(
    values,
    charts.ThemeOptionFunc(charts.ThemeDark),
    charts.TitleOptionFunc(charts.TitleOption{
        Text:  "Sales",
        Theme: nil,  // Use chart theme
    }),
)
```

--------------------------------

### GetFont Example

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/05-fonts-and-themes.md

Example of how to retrieve a registered font.

```go
font, err := charts.GetFont("Arial")
if err != nil {
    return err
}
```

--------------------------------

### ThemeGrafana Example

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/05-fonts-and-themes.md

Example of using the Grafana theme.

```go
charts.ThemeOptionFunc(charts.ThemeGrafana)
```

--------------------------------

### X-Axis Basic Setup

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/09-series-axes-legend-reference.md

Demonstrates the basic setup for an X-axis, typically used for categorical data.

```go
xAxis := charts.NewXAxisOption([]string{
    "Jan", "Feb", "Mar", "Apr", "May",
})

p, _ := charts.LineRender(values, charts.XAxisOptionFunc(xAxis))
```

--------------------------------

### ValueFormatter Example

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/03-types-and-structures.md

An example demonstrating how to create a ValueFormatter function to format numbers as percentages with two decimal places.

```go
formatter := func(v float64) string {
    return fmt.Sprintf("%.2f%%", v)
}
```

--------------------------------

### ThemeAnt Example

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/05-fonts-and-themes.md

Example of using the Ant Design theme.

```go
charts.ThemeOptionFunc(charts.ThemeAnt)
```

--------------------------------

### ThemeDark Example

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/05-fonts-and-themes.md

Example of using the dark theme.

```go
charts.ThemeOptionFunc(charts.ThemeDark)
```

--------------------------------

### Testing Pattern

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/08-usage-patterns-and-examples.md

An example of how to test chart rendering functionality using Go's built-in testing package.

```go
func TestChartRendering(t *testing.T) {
    values := [][]float64{{10, 20, 30}}
    
    p, err := charts.LineRender(values)
    if err != nil {
        t.Errorf("Render failed: %v", err)
    }
    
    data, err := p.Bytes()
    if err != nil {
        t.Errorf("Export failed: %v", err)
    }
    
    if len(data) == 0 {
        t.Error("No data generated")
    }
}
```

--------------------------------

### Line Chart with Full Configuration

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/08-usage-patterns-and-examples.md

Renders a line chart with extensive configuration options.

```go
p, err := charts.LineRender(
    values,
    charts.TitleTextOptionFunc("Monthly Sales", "2024"),
    charts.XAxisDataOptionFunc([]string{"Jan", "Feb", "Mar", "Apr", "May"}),
    charts.YAxisOptionFunc(charts.YAxisOption{
        Min: TrueValue(0),
        Max: TrueValue(1000),
    }),
    charts.LegendLabelsOptionFunc([]string{"Product A", "Product B"}, charts.PositionRight),
    charts.WidthOptionFunc(1000),
    charts.HeightOptionFunc(600),
    charts.ThemeOptionFunc(charts.ThemeDark),
    charts.MarkLineOptionFunc(0, charts.SeriesMarkDataTypeAverage),
    charts.MarkPointOptionFunc(0, charts.SeriesMarkDataTypeMax),
)
```

--------------------------------

### Basic Legend Setup

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/09-series-axes-legend-reference.md

Initializing a legend with series names and position.

```go
legend := charts.NewLegendOption(
    []string{"Series 1", "Series 2"},
    charts.PositionRight,
)

p, _ := charts.LineRender(values, charts.LegendOptionFunc(legend))
```

--------------------------------

### Render Example

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/01-chart-render-functions.md

Example usage of the generic Render function with ChartOption and additional options.

```go
opt := charts.ChartOption{
    Type: charts.ChartOutputPNG,
    Width: 800,
    Height: 600,
    SeriesList: seriesList,
    Theme: "dark",
}
p, err := charts.Render(opt, charts.TitleTextOptionFunc("My Chart"))
```

--------------------------------

### Simple Table

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/08-usage-patterns-and-examples.md

Renders a simple table with a header and data rows.

```go
header := []string{"Name", "Age", "City"}
data := [][]string{
    {"Alice", "28", "New York"},
    {"Bob", "35", "San Francisco"},
    {"Charlie", "42", "Boston"},
}

p, err := charts.TableRender(header, data)
```

--------------------------------

### Minimal Line Chart

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/08-usage-patterns-and-examples.md

Renders a basic line chart with minimal configuration.

```go
package main

import (
    "io/ioutil"
    "log"
    charts "github.com/vicanso/go-charts/v2"
)

func main() {
    values := [][]float64{
        {120, 132, 101, 134, 90},
    }
    
    p, err := charts.LineRender(values)
    if err != nil {
        log.Fatal(err)
    }
    
    data, _ := p.Bytes()
    ioutil.WriteFile("chart.png", data, 0644)
}
```

--------------------------------

### ErrFontNotExists Example

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/00-overview-and-index.md

Example of how to handle the ErrFontNotExists error when retrieving a font.

```go
font, err := charts.GetFont("MissingFont")
if err == charts.ErrFontNotExists {
    // Handle missing font
}
```

--------------------------------

### Pie Chart Example

Source: https://github.com/vicanso/go-charts/blob/main/README.md

Demonstrates the creation of a pie chart with options for title, padding, legend, and showing data labels.

```go
package main

import (
	"github.com/vicanso/go-charts/v2"
)

func main() {
	values := []float64{
		1048,
		735,
		580,
		484,
		300,
	}
	p, err := charts.PieRender(
		values,
		charts.TitleOptionFunc(charts.TitleOption{
			Text:    "Rainfall vs Evaporation",
			Subtext: "Fake Data",
			Left:    charts.PositionCenter,
		}),
		charts.PaddingOptionFunc(charts.Box{
			Top:    20,
			Right:  20,
			Bottom: 20,
			Left:   20,
		}),
		charts.LegendOptionFunc(charts.LegendOption{
			Orient: charts.OrientVertical,
			Data: []string{
				"Search Engine",
				"Direct",
				"Email",
				"Union Ads",
				"Video Ads",
			},
			Left: charts.PositionLeft,
		}),
		charts.PieSeriesShowLabel(),
	)
	if err != nil {
		panic(err)
	}

	buf, err := p.Bytes()
	if err != nil {
		panic(err)
	}
	// snip...	
}
```

--------------------------------

### Simple Pie Chart

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/08-usage-patterns-and-examples.md

Renders a simple pie chart with labels and data.

```go
values := []float64{1048, 735, 580, 484, 300}

p, err := charts.PieRender(
    values,
    charts.TitleTextOptionFunc("Market Share"),
    charts.LegendLabelsOptionFunc([]string{
        "Product A", "Product B", "Product C", "Product D", "Other",
    }),
    charts.PieSeriesShowLabel(),
)
```

--------------------------------

### HTTP Handler Pattern

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/08-usage-patterns-and-examples.md

An example of how to use go-charts within an HTTP handler to generate charts dynamically based on request parameters.

```go
func chartHandler(w http.ResponseWriter, r *http.Request) {
    chartType := r.URL.Query().Get("type")  // "line", "bar", etc.
    
    values := [][]float64{
        {100, 200, 150, 300},
    }
    
    var p *charts.Painter
    var err error
    
    switch chartType {
    case "bar":
        p, err = charts.BarRender(values)
    case "pie":
        p, err = charts.PieRender(values[0])
    default:
        p, err = charts.LineRender(values)
    }
    
    if err != nil {
        http.Error(w, "Render failed", 500)
        return
    }
    
    data, _ := p.Bytes()
    
    w.Header().Set("Content-Type", "image/png")
    w.Write(data)
}
```

--------------------------------

### Quick Start

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/00-overview-and-index.md

This code snippet demonstrates how to quickly generate a line chart using go-charts, set its title, X-axis data, and legend labels, and then export it to a PNG file.

```go
package main

import (
    "io/ioutil"
    "log"
    charts "github.com/vicanso/go-charts/v2"
)

func main() {
    // Data: 2 series with 5 values each
    values := [][]float64{
        {10, 20, 30, 40, 50},
        {15, 25, 35, 45, 55},
    }
    
    // Render with title and legend
    p, err := charts.LineRender(
        values,
        charts.TitleTextOptionFunc("Sales"),
        charts.XAxisDataOptionFunc([]string{"A", "B", "C", "D", "E"}),
        charts.LegendLabelsOptionFunc([]string{"Q1", "Q2"}),
    )
    if err != nil {
        log.Fatal(err)
    }
    
    // Export to PNG bytes
    data, _ := p.Bytes()
    ioutil.WriteFile("chart.png", data, 0644)
}
```

--------------------------------

### TableRender Example

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/01-chart-render-functions.md

Example usage of the TableRender function to create a table with headers, data, and column spans.

```go
header := []string{"Name", "Age", "Address", "Tag"}
data := [][]string{
    {"John Brown", "32", "New York No. 1", "nice, dev"},
    {"Jim Green", "42", "London No. 1", "wow"},
    {"Joe Black", "32", "Sidney No. 1", "cool, teacher"},
}
spans := map[int]int{
    0: 2, // First column spans 2 columns
    1: 1,
    2: 3,
    3: 2,
}
p, err := charts.TableRender(header, data, spans)
```

--------------------------------

### Color Parsing Example

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/05-fonts-and-themes.md

Internal function to parse color from hex strings.

```go
// Used internally, accessible through Color type
color := charts.parseColor("#FF0000")  // Red
color := charts.parseColor("#00FF00")  // Green
```

--------------------------------

### Bar Chart with Custom Styling

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/08-usage-patterns-and-examples.md

Renders a bar chart with custom styling options.

```go
opt := charts.ChartOption{
    Type:       charts.ChartOutputPNG,
    Width:      1200,
    Height:     600,
    Theme:      charts.ThemeAnt,
    BarWidth:   30,
    BarMargin:  5,
    SeriesList: charts.NewSeriesListDataFromValues(values, charts.ChartTypeBar),
    XAxis:      charts.NewXAxisOption(categories),
    Title: charts.TitleOption{
        Text: "Sales by Region",
        Left: charts.PositionCenter,
    },
}

p, err := charts.Render(opt)
```

--------------------------------

### ErrFontNotExists Error

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/07-utilities-and-configuration.md

Error returned when a requested font is not installed.

```go
var ErrFontNotExists = errors.New("font is not exists")
```

```go
font, err := charts.GetFont("NonExistent")
if err == charts.ErrFontNotExists {
    // Font not found
}
```

--------------------------------

### Sales Funnel

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/08-usage-patterns-and-examples.md

Renders a funnel chart to visualize a sales pipeline.

```go
values := []float64{100, 80, 60, 40, 20}

p, err := charts.FunnelRender(
    values,
    charts.TitleTextOptionFunc("Sales Pipeline"),
    charts.LegendLabelsOptionFunc([]string{
        "Impression", "Click", "Visit", "Inquiry", "Order",
    }),
)
```

--------------------------------

### TableOptionRender Example

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/01-chart-render-functions.md

Example usage of the TableOptionRender function with a TableChartOption struct.

```go
opt := charts.TableChartOption{
    Header: []string{"Col1", "Col2", "Col3"},
    Data: [][]string{
        {"A", "B", "C"},
        {"D", "E", "F"},
    },
    Width:  800,
    Type:   charts.ChartOutputPNG,
    Theme:  charts.NewTheme("dark"),
}
p, err := charts.TableOptionRender(opt)
```

--------------------------------

### Set Global Defaults

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/08-usage-patterns-and-examples.md

Configures global default width and height for charts, which will be used unless explicitly overridden.

```go
// Set once on startup
charts.SetDefaultWidth(800)
charts.SetDefaultHeight(600)

// All subsequent charts use these unless overridden
p, _ := charts.LineRender(values)
```

--------------------------------

### Reuse Painters

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/08-usage-patterns-and-examples.md

Optimizes performance by creating a base painter once and rendering multiple charts onto it before exporting.

```go
// Create base painter
p, _ := charts.NewPainter(charts.PainterOptions{
    Type:   charts.ChartOutputPNG,
    Width:  1000,
    Height: 600,
})

// Render multiple charts on it
opt1.Parent = p
charts.Render(opt1)

opt2.Parent = p
charts.Render(opt2)

// Single export
data, _ := p.Bytes()
```

--------------------------------

### Table with Custom Styling

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/08-usage-patterns-and-examples.md

Demonstrates how to create a table chart with custom font sizes, background colors for headers and rows, and specific cell text styling.

```go
opt := charts.TableChartOption{
    Type:       charts.ChartOutputPNG,
    Width:      900,
    Header:     header,
    Data:       data,
    FontSize:   12,
    FontFamily: "Arial",
    HeaderBackgroundColor: charts.Color{R: 66, G: 135, B: 245, A: 255},
    HeaderFontColor:       charts.Color{R: 255, G: 255, B: 255, A: 255},
    RowBackgroundColors: []charts.Color{
        charts.Color{R: 245, G: 245, B: 245, A: 255},
        charts.Color{R: 255, G: 255, B: 255, A: 255},
    },
    CellTextStyle: func(cell charts.TableCell) *charts.Style {
        if cell.Row == 0 {
            return &charts.Style{FontSize: 14}
        }
        return nil
    },
}

p, err := charts.TableOptionRender(opt)
```

--------------------------------

### Line Chart Example

Source: https://github.com/vicanso/go-charts/blob/main/README.md

Demonstrates how to create a line chart using the go-charts library. It includes options for title, X-axis data, and legend labels.

```go
package main

import (
	charts "github.com/vicanso/go-charts/v2"
)

func main() {
	values := [][]float64{
		{
			120,
			132,
			101,
			134,
			90,
			230,
			210,
		},
		{
			// snip...
		},
		{
			// snip...
		},
		{
			// snip...
		},
		{
			// snip...
		},
	}
	p, err := charts.LineRender(
		values,
		charts.TitleTextOptionFunc("Line"),
		charts.XAxisDataOptionFunc([]string{
			"Mon",
			"Tue",
			"Wed",
			"Thu",
			"Fri",
			"Sat",
			"Sun",
		}),
		charts.LegendLabelsOptionFunc([]string{
			"Email",
			"Union Ads",
			"Video Ads",
			"Direct",
			"Search Engine",
		}, charts.PositionCenter),
	)

	if err != nil {
		panic(err)
	}

	buf, err := p.Bytes()
	if err != nil {
		panic(err)
	}
	// snip...
}
```

--------------------------------

### Percentage Y-Axis Configuration

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/09-series-axes-legend-reference.md

Example of configuring a Y-axis to display percentages.

```go
yAxis := charts.YAxisOption{
    Min:       charts.FloatPtr(0),
    Max:       charts.FloatPtr(100),
    Formatter: "{value}%",
}
```

--------------------------------

### RenderEChartsToPNG Example

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/06-echarts-compatibility.md

Example usage of the RenderEChartsToPNG function with a sample ECharts JSON.

```go
jsonOptions := `{
    "title": {
        "text": "Line Chart"
    },
    "xAxis": {
        "data": ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"]
    },
    "series": [{
        "data": [150, 230, 224, 218, 135, 147, 260]
    }]
}`
data, err := charts.RenderEChartsToPNG(jsonOptions)
if err != nil {
    log.Fatal(err)
}
```

--------------------------------

### Performance Metrics Radar

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/08-usage-patterns-and-examples.md

Renders a radar chart to display performance metrics.

```go
values := [][]float64{
    {4200, 3000, 20000, 35000, 50000, 18000},  // Budget
    {3000, 2500, 18000, 30000, 45000, 20000},  // Actual
}

p, err := charts.RadarRender(
    values,
    charts.TitleTextOptionFunc("Q1 Performance"),
    charts.LegendLabelsOptionFunc([]string{"Budget", "Actual"}),
    charts.RadarIndicatorOptionFunc(
        []string{"Sales", "Admin", "IT", "Support", "Dev", "Marketing"},
        []float64{6500, 16000, 30000, 38000, 52000, 25000},
    ),
)
```

--------------------------------

### Graceful Error Handling

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/08-usage-patterns-and-examples.md

Illustrates how to handle potential errors during chart rendering and data export.

```go
p, err := charts.LineRender(values, options...)
if err != nil {
    log.Printf("Chart rendering failed: %v", err)
    // Return error response or default image
    return nil, err
}

data, err := p.Bytes()
if err != nil {
    log.Printf("Chart export failed: %v", err)
    return nil, err
}
```

--------------------------------

### Bar Chart Example

Source: https://github.com/vicanso/go-charts/blob/main/README.md

Illustrates how to generate a bar chart with options for X-axis data, legend labels, and mark lines/points for average and max/min values.

```go
package main

import (
	"github.com/vicanso/go-charts/v2"
)

func main() {
	values := [][]float64{
		{
			2.0,
			4.9,
			7.0,
			23.2,
			25.6,
			76.7,
			135.6,
			162.2,
			32.6,
			20.0,
			6.4,
			3.3,
		},
		{
			// snip...	
		},
	}
	p, err := charts.BarRender(
		values,
		charts.XAxisDataOptionFunc([]string{
			"Jan",
			"Feb",
			"Mar",
			"Apr",
			"May",
			"Jun",
			"Jul",
			"Aug",
			"Sep",
			"Oct",
			"Nov",
			"Dec",
		}),
		charts.LegendLabelsOptionFunc([]string{
			"Rainfall",
			"Evaporation",
		}, charts.PositionRight),
		charts.MarkLineOptionFunc(0, charts.SeriesMarkDataTypeAverage),
		charts.MarkPointOptionFunc(0, charts.SeriesMarkDataTypeMax,
			charts.SeriesMarkDataTypeMin),
		// custom option func
		func(opt *charts.ChartOption) {
			opt.SeriesList[1].MarkPoint = charts.NewMarkPoint(
				charts.SeriesMarkDataTypeMax,
				charts.SeriesMarkDataTypeMin,
			)
			opt.SeriesList[1].MarkLine = charts.NewMarkLine(
				charts.SeriesMarkDataTypeAverage,
			)
		},
	)
	if err != nil {
		panic(err)
	}

	buf, err := p.Bytes()
	if err != nil {
		panic(err)
	}
	// snip...
}
```

--------------------------------

### FunnelRender Example

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/01-chart-render-functions.md

Example usage of the FunnelRender function to create a funnel chart with specified data and options.

```go
values := []float64{100, 80, 60, 40, 20}
p, err := charts.FunnelRender(
    values,
    charts.TitleTextOptionFunc("Sales Funnel"),
    charts.LegendLabelsOptionFunc([]string{"Show", "Click", "Visit", "Inquiry", "Order"}),
)
```

--------------------------------

### RadarRender Example

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/01-chart-render-functions.md

Example usage of the RadarRender function to create a radar chart with specified data and options.

```go
values := [][]float64{
    {4200, 3000, 20000, 35000, 50000, 18000},
    {2800, 2500, 18000, 30000, 45000, 20000},
}
p, err := charts.RadarRender(
    values,
    charts.TitleTextOptionFunc("Performance Metrics"),
    charts.LegendLabelsOptionFunc([]string{"Budget", "Actual"}),
    charts.RadarIndicatorOptionFunc(
        []string{"Sales", "Admin", "IT", "Support", "Dev", "Marketing"},
        []float64{6500, 16000, 30000, 38000, 52000, 25000},
    ),
)
```

--------------------------------

### Formatter for Axis Labels

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/09-series-axes-legend-reference.md

Examples of how to format axis labels with units.

```go
yAxis.Formatter = "{value} %"    // "10 %", "20 %", etc.
yAxis.Formatter = "{value} kg"   // "10 kg", "20 kg", etc.
```

--------------------------------

### Example: Complete ECharts Option

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/06-echarts-compatibility.md

A comprehensive example of an ECharts JSON configuration including title, legend, axes, and series.

```json
{
    "type": "png",
    "theme": "dark",
    "width": 1000,
    "height": 600,
    "padding": [40, 40, 40, 40],
    "title": {
        "text": "Sales Dashboard",
        "subtext": "2024 Q1",
        "left": "center",
        "top": "20",
        "textStyle": {
            "fontSize": 20,
            "color": "#333333"
        }
    },
    "legend": {
        "data": ["Series 1", "Series 2"],
        "left": "center",
        "top": "60",
        "orient": "horizontal"
    },
    "xAxis": {
        "type": "category",
        "data": ["Jan", "Feb", "Mar", "Apr", "May", "Jun"]
    },
    "yAxis": {
        "type": "value",
        "min": 0,
        "max": 1000
    },
    "series": [
        {
            "name": "Series 1",
            "type": "line",
            "data": [100, 150, 200, 180, 220, 250]
        },
        {
            "name": "Series 2",
            "type": "line",
            "data": [80, 120, 160, 140, 180, 200]
        }
    ]
}
```

--------------------------------

### Side-by-Side Charts

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/08-usage-patterns-and-examples.md

Composes multiple charts side-by-side within a single image.

```go
// Create two line charts
opt1 := charts.ChartOption{
    SeriesList: charts.NewSeriesListDataFromValues(values1, charts.ChartTypeLine),
    Width:      500,
    Height:     400,
    Box:        charts.Box{Left: 0, Top: 0, Right: 500, Bottom: 400},
}

opt2 := charts.ChartOption{
    SeriesList: charts.NewSeriesListDataFromValues(values2, charts.ChartTypeLine),
    Width:      500,
    Height:     400,
    Box:        charts.Box{Left: 500, Top: 0, Right: 1000, Bottom: 400},
}

// Create main painter
p, _ := charts.NewPainter(charts.PainterOptions{
    Type:   charts.ChartOutputPNG,
    Width:  1000,
    Height: 400,
})

// Render both charts
opt1.Parent = p
opt2.Parent = p
charts.Render(opt1)
charts.Render(opt2)

data, _ := p.Bytes()
```

--------------------------------

### Built-in Humanize Formatter

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/04-painter-and-rendering.md

Example of using a built-in formatter for human-readable numeric values.

```go
// Returns "1.2K", "3.4M", etc.
```

--------------------------------

### Font Fallback

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/08-usage-patterns-and-examples.md

Demonstrates a fallback mechanism for fonts, ensuring a default font is used if a custom font cannot be loaded.

```go
fontFamily := "CustomFont"
charts.InstallFont(fontFamily, fontData)

font, err := charts.GetFont(fontFamily)
if err != nil {
    // Fallback to default
    font, _ = charts.GetDefaultFont()
}
```

--------------------------------

### Horizontal Bar Chart Example

Source: https://github.com/vicanso/go-charts/blob/main/README.md

Shows how to create a horizontal bar chart, including options for title, padding, legend labels, and Y-axis data.

```go
package main

import (
	"github.com/vicanso/go-charts/v2"
)

func main() {
	values := [][]float64{
		{
			18203,
			23489,
			29034,
			104970,
			131744,
			630230,
		},
		{
			// snip...	
		},
	}
	p, err := charts.HorizontalBarRender(
		values,
		charts.TitleTextOptionFunc("World Population"),
		charts.PaddingOptionFunc(charts.Box{
			Top:    20,
			Right:  40,
			Bottom: 20,
			Left:   20,
		}),
		charts.LegendLabelsOptionFunc([]string{
			"2011",
			"2012",
		}),
		charts.YAxisDataOptionFunc([]string{
			"Brazil",
			"Indonesia",
			"USA",
			"India",
			"China",
			"World",
		}),
	)
	if err != nil {
		panic(err)
	}

	buf, err := p.Bytes()
	if err != nil {
		panic(err)
	}
	// snip...
}
```

--------------------------------

### X-Axis Show/Hide

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/09-series-axes-legend-reference.md

Example of hiding the X-axis using the 'Show' field.

```go
xAxis.Show = charts.FalseFlag()  // Hide the axis
```

--------------------------------

### Line Chart from ECharts JSON

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/08-usage-patterns-and-examples.md

Renders a line chart by providing ECharts compatible JSON configuration.

```go
json := `{
    "title": {
        "text": "Sales Trend"
    },
    "xAxis": {
        "data": ["Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"]
    },
    "series": [{
        "type": "line",
        "data": [150, 230, 224, 218, 135, 147, 260]
    }]
}`

data, err := charts.RenderEChartsToPNG(json)
```

--------------------------------

### X-Axis Positioning

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/09-series-axes-legend-reference.md

Examples of setting the 'Position' field for an X-axis to move it to the top or bottom.

```go
xAxis.Position = charts.PositionTop      // Move to top
xAxis.Position = charts.PositionBottom   // Bottom (default)
```

--------------------------------

### Bar Chart from ECharts JSON

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/08-usage-patterns-and-examples.md

Renders a bar chart by providing ECharts compatible JSON configuration.

```go
json := `{ 
    "title": {"text": "Monthly Revenue"},
    "xAxis": {
        "type": "category",
        "data": ["Jan", "Feb", "Mar", "Apr", "May"]
    },
    "yAxis": {
        "type": "value"
    },
    "series": [{
        "type": "bar",
        "data": [1000, 1200, 1500, 1800, 2100]
    }]
}`

data, err := charts.RenderEChartsToPNG(json)
```

--------------------------------

### Series with Custom Styling

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/08-usage-patterns-and-examples.md

Defines a series with specific styling, including stroke color, width, and marking the maximum point.

```go
seriesList := charts.SeriesList{
    {
        Type: charts.ChartTypeLine,
        Data: charts.NewSeriesDataFromValues([]float64{10, 20, 30}),
        Name: "Series 1",
        Style: charts.Style{
            StrokeColor: charts.Color{R: 255, G: 0, B: 0, A: 255},
            StrokeWidth: 2,
        },
        MarkPoint: charts.NewMarkPoint(charts.SeriesMarkDataTypeMax),
    },
}
```

--------------------------------

### NewMarkPoint

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/07-utilities-and-configuration.md

Creates mark point configuration.

```go
func NewMarkPoint(markPointTypes ...string) SeriesMarkPoint
```

```go
mp := charts.NewMarkPoint(
    charts.SeriesMarkDataTypeMax,
    charts.SeriesMarkDataTypeMin,
)
```

--------------------------------

### NewMarkLine

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/07-utilities-and-configuration.md

Creates mark line configuration.

```go
func NewMarkLine(markLineTypes ...string) SeriesMarkLine
```

```go
ml := charts.NewMarkLine(
    charts.SeriesMarkDataTypeAverage,
    charts.SeriesMarkDataTypeMax,
)
```

--------------------------------

### NewXAxisOption

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/07-utilities-and-configuration.md

Creates X-axis configuration.

```go
func NewXAxisOption(data []string, boundaryGap ...*bool) XAxisOption
```

```go
opt := charts.NewXAxisOption(
    []string{"Jan", "Feb", "Mar"},
    charts.TrueFlag(),
)
```

--------------------------------

### GetDefaultFont Function Signature

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/05-fonts-and-themes.md

Gets the default font (pre-installed Roboto).

```go
func GetDefaultFont() (*truetype.Font, error)
```

--------------------------------

### NewLegendOption

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/07-utilities-and-configuration.md

Creates legend configuration.

```go
func NewLegendOption(labels []string, left ...string) LegendOption
```

```go
opt := charts.NewLegendOption(
    []string{"Series 1", "Series 2"},
    charts.PositionRight,
)
```

--------------------------------

### NewPieSeriesList

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/07-utilities-and-configuration.md

Creates a series list for pie charts.

```go
func NewPieSeriesList(values []float64) SeriesList
```

```go
values := []float64{1048, 735, 580, 484}
seriesList := charts.NewPieSeriesList(values)
p, _ := charts.PieRender(values)
```

--------------------------------

### NewFunnelSeriesList

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/07-utilities-and-configuration.md

Creates a series list for funnel charts.

```go
func NewFunnelSeriesList(values []float64) SeriesList
```

```go
values := []float64{100, 80, 60, 40, 20}
seriesList := charts.NewFunnelSeriesList(values)
```

--------------------------------

### NewYAxisOptions

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/07-utilities-and-configuration.md

Creates Y-axis configurations.

```go
func NewYAxisOptions(data []string, others ...[]string) []YAxisOption
```

```go
opts := charts.NewYAxisOptions(
    []string{"A", "B", "C"},
    []string{"1", "2", "3"},
)
```

--------------------------------

### PainterStyleOption function

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/04-painter-and-rendering.md

Sets initial style.

```go
func PainterStyleOption(style Style) PainterOption
```

--------------------------------

### NewSeriesLabelPainter

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/07-utilities-and-configuration.md

Creates series label renderer.

```go
func NewSeriesLabelPainter(params SeriesLabelPainterParams) *SeriesLabelPainter
```

--------------------------------

### NewPainter

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/04-painter-and-rendering.md

Creates a new painter instance.

```go
func NewPainter(opts PainterOptions, opt ...PainterOption) (*Painter, error)
```

```go
p, err := charts.NewPainter(charts.PainterOptions{
    Type:   charts.ChartOutputPNG,
    Width:  800,
    Height: 600,
})
if err != nil {
    log.Fatal(err)
}
```

--------------------------------

### Use Custom Font

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/00-overview-and-index.md

Installs a custom font and renders a line chart using it.

```go
charts.InstallFont("MyFont", fontData)
p, _ := charts.LineRender(values, charts.FontFamilyOptionFunc("MyFont"))
```

--------------------------------

### Child method

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/04-painter-and-rendering.md

Creates a child painter with inherited properties.

```go
func (p *Painter) Child(opt ...PainterOption) *Painter
```

```go
child := p.Child(
    charts.PainterPaddingOption(charts.Box{Top: 20, Left: 20}),
)
```

--------------------------------

### Series Type Field

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/09-series-axes-legend-reference.md

Examples of setting the 'Type' field for different chart types.

```go
series.Type = charts.ChartTypeLine     // "line"
series.Type = charts.ChartTypeBar      // "bar"
series.Type = charts.ChartTypePie      // "pie"
series.Type = charts.ChartTypeRadar    // "radar"
series.Type = charts.ChartTypeFunnel   // "funnel"
series.Type = charts.ChartTypeHorizontalBar  // "horizontalBar"
```

--------------------------------

### TitleTextOptionFunc

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/02-option-functions.md

Sets title and optional subtitle text.

```go
func TitleTextOptionFunc(text string, subtext ...string) OptionFunc
```

```go
charts.TitleTextOptionFunc("Sales Dashboard", "Q1 2024")
```

--------------------------------

### TitleOptionFunc

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/02-option-functions.md

Sets complete title configuration with positioning and styling.

```go
func TitleOptionFunc(title TitleOption) OptionFunc
```

```go
charts.TitleOptionFunc(charts.TitleOption{
    Text:    "Dashboard",
    Subtext: "Monthly Report",
    Left:    charts.PositionCenter,
    Top:     "20",
})
```

--------------------------------

### Dual Y-Axis Chart

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/08-usage-patterns-and-examples.md

Configures a chart with two independent Y-axes, each with its own min/max range and positioning.

```go
opt := charts.ChartOption{
    SeriesList: seriesList,
    XAxis:      charts.NewXAxisOption(categories),
    YAxisOptions: []charts.YAxisOption{
        {
            Min: FloatPtr(0),
            Max: FloatPtr(100),
        },
        {
            Min: FloatPtr(0),
            Max: FloatPtr(1000),
            Position: charts.PositionRight,
        },
    },
    Title: charts.TitleOption{Text: "Multi-axis Chart"},
}

p, err := charts.Render(opt)
```

--------------------------------

### Pie Chart with Custom Legend Position

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/08-usage-patterns-and-examples.md

Renders a pie chart with a custom legend position.

```go
p, err := charts.PieRender(
    values,
    charts.LegendOptionFunc(charts.LegendOption{
        Data:   []string{"Search", "Direct", "Email", "Ads"},
        Orient: charts.OrientVertical,
        Left:   charts.PositionLeft,
        Top:    charts.PositionCenter,
    }),
)
```

--------------------------------

### Creating Series from Raw Values

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/09-series-axes-legend-reference.md

Demonstrates how to create a single series or multiple series directly from raw float64 values.

```go
// Single series
series := charts.NewSeriesFromValues([]float64{10, 20, 30})

// Multiple series
seriesList := charts.NewSeriesListDataFromValues([][]float64{
    {10, 20, 30},
    {15, 25, 35},
})
```

--------------------------------

### Grouped Bar Chart

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/08-usage-patterns-and-examples.md

Renders a grouped bar chart comparing two sets of data.

```go
values := [][]float64{
    {2.0, 4.9, 7.0, 23.2, 25.6},      // Group 1
    {1.5, 3.2, 5.5, 20.1, 22.8},      // Group 2
}

p, err := charts.BarRender(
    values,
    charts.XAxisDataOptionFunc([]string{"Jan", "Feb", "Mar", "Apr", "May"}),
    charts.LegendLabelsOptionFunc([]string{"2023", "2024"}),
    charts.TitleTextOptionFunc("Monthly Rainfall Comparison"),
)
```

--------------------------------

### Get Min/Max Values from Series

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/09-series-axes-legend-reference.md

Retrieving the minimum and maximum values for a given Y-axis.

```go
max, min := seriesList.GetMaxMin(0)  // For first Y-axis
```

--------------------------------

### NewGridPainter

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/07-utilities-and-configuration.md

Creates grid renderer for table layouts.

```go
func NewGridPainter(p *Painter, opt GridPainterOption) *gridPainter
```

```go
grid := charts.NewGridPainter(p, charts.GridPainterOption{
    Column: 3,
    Row:    4,
    StrokeWidth: 1,
    StrokeColor: charts.Color{R: 200, G: 200, B: 200, A: 255},
})
```

--------------------------------

### Series Name Field

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/09-series-axes-legend-reference.md

Example of setting the 'Name' field for a series, which is used in the legend and labels.

```go
series.Name = "Revenue"  // Appears in legend
```

--------------------------------

### ThemeOptionFunc

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/02-option-functions.md

Sets chart theme.

```go
func ThemeOptionFunc(theme string) OptionFunc
```

```go
charts.ThemeOptionFunc("dark")
```

--------------------------------

### Custom Value Formatter

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/08-usage-patterns-and-examples.md

Applies a custom function to format the display of values on the chart axes or tooltips.

```go
opt := charts.ChartOption{
    SeriesList: seriesList,
    ValueFormatter: func(v float64) string {
        if v > 1000000 {
            return fmt.Sprintf("%.1fM", v/1000000)
        } else if v > 1000 {
            return fmt.Sprintf("%.1fK", v/1000)
        }
        return fmt.Sprintf("%.0f", v)
    },
}

p, err := charts.Render(opt)
```

--------------------------------

### PainterOptions struct

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/04-painter-and-rendering.md

Configuration struct for painter creation.

```go
type PainterOptions struct {
    Type   string
    Width  int
    Height int
    Font   *truetype.Font
}
```

--------------------------------

### LineChartOption

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/04-painter-and-rendering.md

Configuration options for rendering a line chart.

```go
type LineChartOption struct {
    Theme              ColorPalette
    Font               *truetype.Font
    SeriesList         SeriesList
    XAxis              XAxisOption
    Padding            Box
    YAxisOptions       []YAxisOption
    Title              TitleOption
    Legend             LegendOption
    SymbolShow         *bool
    StrokeWidth        float64
    FillArea           bool
    backgroundIsFilled bool
    Opacity            uint8
}
```

--------------------------------

### Pie Series Data

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/06-echarts-compatibility.md

Example of data format for pie charts, where each data item becomes a separate series.

```json
{
    "series": [{
        "type": "pie",
        "data": [
            {"value": 1048, "name": "Search Engine"},
            {"value": 735, "name": "Direct"},
            {"value": 580, "name": "Email"}
        ]
    }]
}
```

--------------------------------

### NewSeriesFromValues

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/07-utilities-and-configuration.md

Creates a single series from numeric array.

```go
func NewSeriesFromValues(values []float64, chartType ...string) Series
```

```go
series := charts.NewSeriesFromValues([]float64{10, 20, 30}, charts.ChartTypeBar)
```

--------------------------------

### Line/Bar Series Data (Named and Colored)

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/06-echarts-compatibility.md

Example of data items with values and names for line or bar series.

```json
{
    "series": [{
        "data": [
            {"value": 100, "name": "Item A"},
            {"value": 200, "name": "Item B"}
        ]
    }]
}
```

--------------------------------

### SeriesList Type

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/03-types-and-structures.md

An array of Series with helper methods for filtering, retrieving names, and getting axis value ranges.

```go
type SeriesList []Series
```

--------------------------------

### Performance Benchmarks

Source: https://github.com/vicanso/go-charts/blob/main/README.md

Benchmarks showing the time per operation (ns/op), bytes per operation (B/op), and allocations per operation (allocs/op) for rendering multi-charts in PNG and SVG formats.

```bash
BenchmarkMultiChartPNGRender-8                78          15216336 ns/op         2298308 B/op       1148 allocs/op
BenchmarkMultiChartSVGRender-8               367           3356325 ns/op        20597282 B/op       3088 allocs/op
```

--------------------------------

### Dark Theme with Custom Colors

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/08-usage-patterns-and-examples.md

Applies a dark theme to a line chart and customizes background and title colors.

```go
p, err := charts.LineRender(
    values,
    charts.ThemeOptionFunc(charts.ThemeDark),
    charts.BackgroundColorOptionFunc(charts.Color{
        R: 30, G: 30, B: 40, A: 255,  // Dark navy
    }),
    charts.TitleOptionFunc(charts.TitleOption{
        Text:      "Dashboard",
        FontColor: charts.Color{R: 255, G: 255, B: 255, A: 255},
    }),
)
```

--------------------------------

### Line/Bar Series Data (Simple Numeric Array)

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/06-echarts-compatibility.md

Example of a simple numeric array for line or bar series data.

```json
{
    "series": [{
        "data": [10, 20, 30, 40]  // Simple numeric array
    }]
}
```

--------------------------------

### PieChartOption

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/04-painter-and-rendering.md

Configuration options for rendering a pie chart.

```go
type PieChartOption struct {
    Theme              ColorPalette
    Font               *truetype.Font
    SeriesList         SeriesList
    Padding            Box
    Title              TitleOption
    Legend             LegendOption
    backgroundIsFilled bool
}
```

--------------------------------

### Rotated Category Labels

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/09-series-axes-legend-reference.md

Example of rotating category labels on an axis, shown here for an X-axis, by setting the TextRotation property.

```go
xAxis.TextRotation = math.Pi / 4  // 45 degrees
```

--------------------------------

### Creating Pie Chart Series

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/09-series-axes-legend-reference.md

Illustrates how to create a series list for a pie chart from a slice of values, where each value becomes a separate series.

```go
values := []float64{1000, 800, 600}

// Creates 3 series internally:
// Series 0: value=1000
// Series 1: value=800
// Series 2: value=600
seriesList := charts.NewPieSeriesList(values)
```

--------------------------------

### Category Y-Axis (Horizontal Bar)

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/09-series-axes-legend-reference.md

Example of creating a Y-axis with string categories, suitable for horizontal bar charts.

```go
yAxis := charts.NewYAxisOptions([]string{
    "Product A", "Product B", "Product C",
})
```

--------------------------------

### Creating Series from SeriesData Array

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/09-series-axes-legend-reference.md

Shows how to construct a series using a slice of SeriesData, allowing for individual data point styling.

```go
data := []charts.SeriesData{
    {Value: 100, Style: charts.Style{...}},
    {Value: 200, Style: charts.Style{...}},
}

series := charts.Series{
    Type: charts.ChartTypeLine,
    Data: data,
    Name: "Sales",
}
```

--------------------------------

### InstallFont Function Signature

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/05-fonts-and-themes.md

Registers a custom font for use in charts.

```go
func InstallFont(fontFamily string, data []byte) error
```

--------------------------------

### Series Min/Max Fields

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/09-series-axes-legend-reference.md

Example of overriding the axis range for a specific series using 'Min' and 'Max' fields.

```go
min := 0.0
max := 1000.0
series.Min = &min
series.Max = &max
```

--------------------------------

### NewRange

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/07-utilities-and-configuration.md

Creates axis range calculator.

```go
func NewRange(opt AxisRangeOption) axisRange
```

```go
r := charts.NewRange(charts.AxisRangeOption{
    Painter:     p,
    Min:         0,
    Max:         100,
    Size:        500,
    DivideCount: 5,
})
values := r.Values()  // Get axis label values
```

--------------------------------

### PainterThemeOption function

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/04-painter-and-rendering.md

Sets color theme.

```go
func PainterThemeOption(theme ColorPalette) PainterOption
```

--------------------------------

### Thousand-Separator Y-Axis

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/09-series-axes-legend-reference.md

Example of using a custom ValueFormatter for a Y-axis to format numbers, in this case, to display them without decimal places.

```go
opt := charts.ChartOption{
    ValueFormatter: func(v float64) string {
        return fmt.Sprintf("%.0f", v)
    },
}
```

--------------------------------

### Series

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/03-types-and-structures.md

Data series configuration.

```go
type Series struct {
    Type          string
    Data          []SeriesData
    AxisIndex     int
    Style         chart.Style
    Label         SeriesLabel
    Name          string
    Radius        string
    RoundRadius   int
    MarkPoint     SeriesMarkPoint
    MarkLine      SeriesMarkLine
    Min           *float64
    Max           *float64
}
```

--------------------------------

### Series Style Field

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/09-series-axes-legend-reference.md

Example of customizing the visual style of a series, including stroke color, width, and fill color.

```go
series.Style = charts.Style{
    StrokeColor: charts.Color{R: 255, G: 0, B: 0, A: 255},
    StrokeWidth: 2,
    FillColor:   charts.Color{R: 255, G: 200, B: 200, A: 100},
}
```

--------------------------------

### SetTextStyle method

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/04-painter-and-rendering.md

Sets text-specific styling.

```go
func (p *Painter) SetTextStyle(style Style) *Painter
```

--------------------------------

### Simple Series Label Formatting

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/09-series-axes-legend-reference.md

Basic configuration for displaying series names as labels.

```go
series.Label = charts.SeriesLabel{
    Show:      true,
    Formatter: "{b}",  // Just the name
}
```

--------------------------------

### TitleOption Structure

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/03-types-and-structures.md

Configuration for title and subtitle in Go-charts.

```go
type TitleOption struct {
    Theme              ColorPalette
    Text               string
    Subtext            string
    Left               string
    Top                string
    Font               *truetype.Font
    FontSize           float64
    FontColor          Color
    SubtextFontSize    float64
    SubtextFontColor   Color
}
```

--------------------------------

### SplitLineShow for Grid Lines

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/09-series-axes-legend-reference.md

Controlling the visibility of grid lines.

```go
yAxis.SplitLineShow = charts.TrueFlag()   // Show lines
yAxis.SplitLineShow = charts.FalseFlag()  // Hide lines
```

--------------------------------

### Series Radius Field (Pie Charts)

Source: https://github.com/vicanso/go-charts/blob/main/_autodocs/09-series-axes-legend-reference.md

Example of setting the 'Radius' field for pie chart series to control the size of the pie.

```go
series.Radius = "50%"    // Pie radius
series.Radius = "30%"    // Smaller pie
```