> For the complete documentation index, see [llms.txt](https://docs.exploratory.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.exploratory.io/visualization/types/errbar-agg.md).

# Error Bar (Summarized Data)

With the Error Bar (Summarized Data) Chart, you can create an Error Bar using the data which is already summarized/aggregated.

For example, if you have the website access data and the number of conversions (number of people who visited this website and became paid users, for example) like the following.

| Date       | Total Views | Conversion |
| ---------- | ----------- | ---------- |
| 2021-01-01 | 4435        | 123        |
| 2021-01-02 | 5345        | 211        |
| 2021-01-03 | 3851        | 134        |
| 2021-01-04 | 4421        | 183        |
| 2021-01-05 | 4245        | 199        |
| 2021-01-06 | 6113        | 252        |
| 2021-01-07 | 6541        | 258        |
| 2021-01-08 | 6018        | 312        |
| 2021-01-09 | 5109        | 280        |
| :          | :           | :          |

You can create an Error Bar chart with this data by following steps.

* Create a new chart and select "Error Bar (Summarized Data)" Type.
* Select "Ratio" for the Calculation Type.
* Assign "Date" to X Axis.
* Assign "Convertion" to Y Axis.
* Assign "Total Views" to Total Number.
* Select "Circle" for the Marker.

![](/files/-McLqwyIezv4myka679N)

## Assignments

* Calculation Type - You can select an error bar calculation type from the following options. The default is `Mean`.
  * Mean - Average based error bar chart.
  * Ratio (%) - Ratio based error bar chart based on the count of values.
* X-Axis - Assign a column you want to show at X-Axis. If it's a Date / Time column assigned, you can select the aggregation level such as `Month`, `Week`, `Day`, etc. If you assign a Number column, you can choose either `As Number` to treat values as continuous values or `As Text` to treat values as categorical values.
* Y-Axis - Assign a column you want to show at Y-Axis.
  * If the calculation type is `Mean`, assgin the mean value of each group.
  * If the calculation type is `Ratio (%)`, assign the target count of each group.
* Total Number - Assign a column that contains the total number of each group.
* Standard Deviation - Assign a column that contains the standard deviation of each group. Only for the "Mean" Calculation Type.
* Range Type - You can select an error bar range type from the following options. The default is `95% Confidence Interval`.
  * 90% Confidence Interval
  * 95% Confidence Interval
  * 99% Confidence Interval
* Marker - You can select a marker type from the following options. The default is `Bar`.
  * Bar - Suitable for comparing actual values and error bar ranges.
  * Circle - Suitable for comparing error bar ranges.
* Color - Take a look at [Color](/visualization/features/color.md) section for more details.
* Sort By - Assign a column to use for Sorting the X-Axis values. The default is based on either the alphabetic order or the factor level order for Factor type columns.
* Repeat By - You can assign a column to repeat the chart for each of its values. Take a look at [Repeat By](/visualization/features/small-multiple.md) section for more details.
* Orientation - You can choose a chart orientation. Either 'Vertical' or 'Horizontal'.

## Confidence Interval Range Calculation Formula

### Calculation Type: Mean

Formula in R.

```
qt((level + 1)/2, df=n-1) * sd / sqrt(n) 


level: 0.90 (90% Confidence Interval)
       0.95 (95% Confidence Interval)
       0.99 (99% Confidence Interval)
n:     Total Number
sd:    Standard Deviation
```

### Calculation Type: Ratio (%)

Formula in R.

```
qnorm((level + 1)/2) * sqrt(ratio * (1 - ratio)/n)

level: 0.90 (90% Confidence Interval)
       0.95 (95% Confidence Interval)
       0.99 (99% Confidence Interval)
n:     Total Number
ratio: Ratio calculated by dividing 
       the Count by the Total Number. (0-1)
```

## Reference Line

Take a look at [Reference Line](/visualization/features/reference-line.md) section for more details.

## Style

You can change the error bar styles from the "Style" setting at Y-Axis. You can change the followings.

* Line Width: Thickness of the error bars.
* Circle Size: Size of the circle. Available only for "Circle" marker option.
* Horizontal Bar Width: Length of the horizontal bar part of the error bars.

## Highlight

You can change the color of the specific markers such as bars, lines or circles that you pick to stand out from others. See [Highlight](/visualization/features/highlight-1.md) for the detail.

## Category

You can categorize numeric values inside the chart. See [Category(Binning)](/visualization/features/category.md) for the detail.

## Limit Values

You can use Limit Values to filter the categories by the aggregated values. See [Limit Values](/visualization/features/limit.md) for the detail.

## 'Others' Group

If you have many categories, you can reduce the number of categories by changing some category names to 'Others' using the 'Others' Group feature. See ['Others' Group](/visualization/features/others-group.md) for the detail.

## Missing Value Handling

You can use the Missing Value Handling feature to control missing values. See [Missing Value Handling](/visualization/features/missing-value-handling.md) for the detail.

## Show Detail

You can show the detailed data underlying the chart by clicking the chart figure. See [Show Detail](/visualization/features/show-detail.md) for the detail.

## Layout Configuration

Take a look at [Layout Configuration](/visualization/features/layout.md) on how to configure the layout and format.

## Save as an Image

You can save the chart as an image file. See [Save as PNG/SVG](/visualization/features/save.md) for more details.