Introduction

This article looks at the bar chart data objects available in Astrato.

Bar charts are particularly useful when you want to visualize and compare categorical data or discrete values. Here are some scenarios where using a bar chart is appropriate:

Comparing Categories: When you have data divided into distinct categories, such as different products, regions, or time periods, and you want to compare values across these categories. For example, comparing sales performance of different product categories over a specific time period.
Showing Frequency Distribution: When you want to display the frequency distribution of categorical data. Bar charts can help visualize the distribution of data across different categories, making it easy to identify patterns or trends.
Visualizing Rankings or Order: When you want to visualize the ranking or order of items based on a certain metric. Bar charts make it easy to see which categories have the highest or lowest values, helping to identify top performers or areas needing improvement.
Displaying Part-to-Whole Relationships: When you want to illustrate the contribution of each category to the total or the relationship between different parts of a whole. Stacked bar charts or grouped bar charts can be used to display part-to-whole relationships effectively.
Comparing Changes Over Time: When you want to compare changes in categorical data over time. Grouped bar charts or stacked bar charts can be used to show how the values within each category change across different time periods.
Visualizing Survey Results: When you want to visualize the results of a survey or feedback form with multiple response options. Bar charts make it easy to see the distribution of responses across different categories.
Presenting Histograms: When you want to visualize the distribution of continuous data grouped into intervals (bins). Bar charts can be used as histograms to show the frequency distribution of data.
Highlighting Differences or Disparities: When you want to highlight disparities or differences between categories. Bar charts can help draw attention to variations in data, making it easier to identify outliers or areas requiring further investigation.

Figure 1 shows an example of a bar chart being added to a sheet in a workbook.

Introduction
Bar Chart Types
Bar Chart Settings

Bar Chart Types

Astrato already supports multiple bar chart types, and more are planned for the future (these are the greyed-out icons in the toolbar). You can display data in vertical or horizontal orientation (vertical orientation is useful for displaying ranked items). Bar charts in Astrato can be created using one measure and one (or two) dimensions, depending on the chart type.

Chart Icon / Type / Data	Description
Bar Column 1 Dimension, 1 Measure	Compares multiple values, with one bar for each dimension value.
Horizontal Bar 1 Dimension, 1 Measure	Compares multiple values, with one bar for each dimension value.
Stacked Column 2 Dimensions, 1 Measure	Compares the totals of items across separate categories.
Stacked Horizontal Bar 2 Dimensions, 1 Measure	Compares the totals of items across separate categories.
Grouped Column 2 Dimensions, 1 Measure	Compares similar items of the same category.
Grouped Horizontal Bar 2 Dimensions, 1 Measure	Compares similar items of the same category.
Stacked 100% 2 Dimensions, 1 Measure	Compares the share of items across categories, displaying them as a proportion of 100%.
Histogram 1 field	show the distribution of values in the selected field.

Bar Chart Settings

Building a Bar Chart
In the data tab, you define the data to use in the chart and define all the settings for the measures.
A bar chart data can include:
- Two dimensions and one measure
- One dimension and up to 10 measures.
- Up to 10 measures without a dimension.
- Measure Settings
  - Color- set the color and opacity of the bars.
  - Format- set the number format for the measure
  - Show data labels - display the bar value in the chart.
  - Advanced calculation- apply advanced calculations in the chart, such as period-over-period, moving average, and more.
    To learn more, check out this article.
  - Axis- set the axis for the measure, between Primary and Secondary.
- Trendlines
  - Select a measure to calculate the trendline and a type of trendline.
  - Customize the line look and feel.
  - Add multiple trendlines.
- Reference Lines
  - Add a reference line on either axes to show goals or important timestamps.
  - Customize the reference line display.
  - A reference line can have a static or dynamic value set by a variable.
    Using a variable allows users to change the display interactively as part of their data exploration.
    To learn more about how to use variables, check out this article.
Styling a Bar Chart
- Orinetation- select between horizontal and vertical bars display.
- Bar padding- set the padding between the individual bars.
- Bar radius- set the curve radius for the upper corners of the bars
- Round all edges- apply to curve radius also to the bottom corners of the bar.
- Transparent bars- apply gradinet transparency to the bars
- Border- define the bars border settings
- Colors- define how to color the bars and add conditional coloring for the bars.
- Legend- set the legend position and title.
Axes Settings of a Bar Chart
Control the axes display and add grid lines and a scroll bar to improve the chart display.
- Dimension
  - Control the color and display of labels, titles, ticks, and lines.
  - Show axis tooltips: When enabled, hovering over the axis will show a vertical dashed line across the chart (see an example in the image below).
  - Enable continuous axis- automatically set the number of labels on the axis and change it dynamically according to the range of values in the axis.
    (this is the same chart as in the image above when a continuous axis is enabled)
  - Axis labels- Set how labels should behave when they overlap.
    Auto- will distribute labels evenly.
    Show last- will always display the last label.
  - Label length- control the length of the label or keep it auto-fit for the best display.
  - Limit visible domain (scroll bar) -
    Set the limit of data point width or number of data points displayed; if the limit is reached, a scroll bar will appear below the axis.
    * This setting is disabled when the continuous axis is enabled.
    There are two options to set the limit:
    Minimum size- this option is better when building for different screen sizes, as it sets the limit by the number of pixels given for each data point.
    Minimum count- this option is simpler to control when the scroll bar will appear.
  - Gridlines- add vertical grid lines to the chart.
- Measure
  Control the measure axis display and range.
  - Control the color and display of labels, titles, ticks, and lines.
  - Default axis name- Override the axis title with a manual value.
  - Range- control the range of values display on the axis.
  - Gridlines- display horizontal gridline.
  - Axis bands- define ranges of bands that color the chart's background.
    This feature helps show when values vary off the expected range.
    The axis band range can be defined by static values or variables.
    Variable values can be changed either by user inputs or by actions.
    This can be used to create control charts, for example.