> ## Documentation Index
> Fetch the complete documentation index at: https://docs.evidence.studio/llms.txt
> Use this file to discover all available pages before exploring further.
# Reference Line
> Add a reference line inside a chart
```liquid theme={null}
{% line_chart
data="demo.daily_orders"
x="date"
y="sum(total_sales)"
date_grain="month"
%}
{% reference_line
y=3500000
label="Target"
color="red"
/%}
{% /line_chart %}
```
## Examples
### Horizontal Target Line
```liquid theme={null}
{% line_chart
data="demo.daily_orders"
x="date"
y="sum(total_sales)"
date_grain="month"
%}
{% reference_line
y=3500000
label="Target"
color="red"
/%}
{% /line_chart %}
```
### Vertical Line at Date
```liquid theme={null}
{% line_chart
data="demo.daily_orders"
x="date"
y="sum(total_sales)"
date_grain="month"
%}
{% reference_line
x="2021-06-01"
label="Product Launch"
color="green"
/%}
{% /line_chart %}
```
### Reference Lines from Data
````liquid theme={null}
```sql ref_lines
select 2500000 as ref, 'Min Target' as ref_label
union all
select 4000000, 'Stretch Goal'
```
{% bar_chart
data="demo.daily_orders"
x="date"
y="sum(total_sales)"
date_grain="month"
%}
{% reference_line
data="ref_lines"
y="ref"
label="ref_label"
/%}
{% /bar_chart %}
````
### Custom Label Styling
```liquid theme={null}
{% line_chart
data="demo.daily_orders"
x="date"
y="sum(total_sales)"
date_grain="month"
%}
{% reference_line
y=3000000
label="Threshold"
color="orange"
label_options={
position="above_start"
background_color="orange"
color="white"
padding=4
}
line_options={
type="dashed"
width=2
}
/%}
{% /line_chart %}
```
### Multiple Reference Lines
```liquid theme={null}
{% line_chart
data="demo.daily_orders"
x="date"
y="sum(total_sales)"
date_grain="month"
%}
{% reference_line y=2500000 label="Min Target" color="red" /%}
{% reference_line y=4500000 label="Stretch Goal" color="green" /%}
{% /line_chart %}
```
## Attributes
Query name to use for calculating dynamic reference values
Text label to display on the reference line
X-axis value for a vertical reference line (e.g., a date or category)
Y-axis value for a horizontal reference line (e.g., a target or threshold)
Starting x-coordinate for a sloped line
Starting y-coordinate for a sloped line
Ending x-coordinate for a sloped line
Ending y-coordinate for a sloped line
Color of the reference line
Styling options for the label
**Example:**
```
label_options={
position = "above_end"
align = "left"
color = "string"
background_color = "string"
padding = 0
fmt = "date"
hide_value = true
border = {
width = 0
type = "solid"
color = "string"
radius = 0
}
text = {
size = 0
bold = true
italic = true
}
}
```
**Attributes:**
* position: `string`
* **Allowed values:**
* `above_end`
* `above_start`
* `above_center`
* `below_end`
* `below_start`
* `below_center`
* align: `string`
* **Allowed values:**
* `left`
* `center`
* `right`
* color: `string`
* background\_color: `string`
* padding: `number`
* fmt: `string` - Format the label value. Defaults to series or axis fmt.
* **Allowed values:** See [Value Formatting](/core-concepts/value-formatting) for all available formats.
* hide\_value: `boolean`
* border: `options group`
* **Options:**
* width: `number`
* type: `string`
* **Allowed values:**
* `solid`
* `dashed`
* `dotted`
* color: `string`
* radius: `number`
* text: `options group`
* **Options:**
* size: `number`
* bold: `boolean`
* italic: `boolean`
Styling options for the line itself
**Example:**
```
line_options={
color = "string"
width = 0
type = "solid"
opacity = 0
}
```
**Attributes:**
* color: `string`
* width: `number` - Width of the line
* type: `string`
* **Allowed values:**
* `solid`
* `dashed`
* `dotted`
* opacity: `number` - Between 0 and 1
Symbol shapes to display at line endpoints
**Example:**
```
symbols={
start = {
shape = "circle"
size = 0
}
end = {
shape = "circle"
size = 0
}
}
```
**Attributes:**
* start: `options group`
* **Options:**
* shape: `string`
* **Allowed values:**
* `circle`
* `emptyCircle`
* `rect`
* `roundRect`
* `triangle`
* `diamond`
* `pin`
* `arrow`
* `none`
* `image://`
* `path://`
* size: `number`
* end: `options group`
* **Options:**
* shape: `string`
* **Allowed values:**
* `circle`
* `emptyCircle`
* `rect`
* `roundRect`
* `triangle`
* `diamond`
* `pin`
* `arrow`
* `none`
* `image://`
* `path://`
* size: `number`
## Allowed Parents
* [area\_chart](/components/area_chart)
* [bar\_chart](/components/bar_chart)
* [bubble\_chart](/components/bubble_chart)
* [combo\_chart](/components/combo_chart)
* [horizontal\_bar\_chart](/components/horizontal_bar_chart)
* [line\_chart](/components/line_chart)
* [scatter\_chart](/components/scatter_chart)