Bar Chart

• Overview
• Chart building
• Single-Series bar chart
• Multi-Series bar chart
• Multi-Series bar chart grouped by series
• 3D bar chart
• 3D bar chart clustered by Z Axis
• Axes management
• Positioning
• Inversion
• Minimum and Maximum values control
• Paddings between bars and bar groups
• Using styles
• Simple style sample
• Application of different styles to chart elements
• Predefined styles
• Working with data labels and tooltips
• Using markers
• Working with colors and color palettes
• Setting colors to the elements
• Color palettes
• Working with hatch fills and hatch palettes
• Setting hatch fills to the elements
• Hatch palettes

Overview

A bar chart, is a chart with rectangular bars of lengths usually proportional to the magnitudes or frequencies of what they represent. Although the bars can be horizontally or vertically oriented, we call vertically oriented charts - column charts and study them in a Column Chart Help section.

Bar charts are useful for showing data changes over a period of time or for illustrating comparisons among items. In bar charts, categories are typically organized along the vertical axis and values along the horizontal axis.

Consider using a bar chart when:

• The axis labels are long.
• The values that are shown are durations.

Chart building

Depending on data model and the visualization purpose the bar chart may contain single series or multi series. AnyChart solution allows to build both 2D (two-dimensional) and 3D (three-dimensional) bar charts.

Single-Series Bar Chart

Let's see single series bar chart created using the following data - sales of ACME Corp. apparel through different retail channels in one year:

Retail Channel	Sales
Department Stores	$637.166
Discount Stores	$721.630
Men's/Women's Specialty Stores	$148.662
Juvenile Specialty Stores	$78.662
All other outlets	$90.000

Now we need to convert this data table into XML, this format will be accepted by AnyChart. In terms of AnyChart data model we have one series of data (Sales) with categories that hold Retail channels names. Each point in series represents one channels and sales amount through this channel. Converted XML Data looks like:

As you can see, we've created one <series> node, specified its type="Bar", added several <point> nodes and set name attribute that defines bar category and y attribute that defines bar value.

All we need to do to finalize bar chart XML creation is to define plot_type="CategorizedHorizontal" in <chart> node and add axes titles. Here it is - AnyChart can now visualize your data. Look at the chart sample below and click on on it to see Live Flash Chart preview and full configured XML.

Multi-series bar chart

To compare two or more data rows you have to use multi-series bar charts as it shown in the sample below.

Let's compare year 2003 sales to year 2004 sales:

Retail Channel	Year 2003 Sales	Year 2004 Sales
Department Stores	$637.166	$737.166
Discount Stores	$721.630	$537.166
Men's/Women's Specialty Stores	$148.662	$188.662
Juvenile Specialty Stores	$78.662	$178.662
All other outlets	$90.000	$89.000

As we do in single-series bar sample above we need to convert this table into XML, the only difference between these two samples is the fact that now we have two series of data - one series for each year, and we give proper names to each series:

As we now have multi-series chart we don't want to set type for each series individually (there can be much more than two series in multi-series chart), so we add <data_plot_settings default_series_type="Bar"/> node to <chart>. Now all series in chart will be of Bar type by default.

Multi-Series Bar Chart grouped by series

Sometimes it is useful to visualize comparison in a different way - group bars be series. In our sample it means that we want to compare sales of all managers in each quarter, not each manager sales in different quarters. You don't have to reformat your data to do this - all you need to do is to switch plot_type attribute to "CategorizedBySeriesHorizontal". Look at the resulting chart below:

3D Bar chart

It is very easy to display the data from the sample above in 3D mode - just set enable_3d_mode attribute and bars will become 3D: <data_plot_settings enable_3d_mode="True">

3D Bar chart clustered by Z Axis

In 3D mode you may want to show bars one over another - in other words cluster them along Z Axis. To do this you need to change scale mode of Y Axis to "Overlay":

Also, we will tune up 3D visualization by setting z_aspect="0.7" and z_padding="0.3". z_aspect attribute controls the depth of 3D plot (0 stands for 2D - flat plot), z_padding controls the space between the clustered elements along Z Axis.

Axes management

In AnyChart axis is an object that allows you to configure chart grid, axis line along with tick marks and labels, axis scale and settings and many more. All axis features are described in Axes Basics , Axes Scales and Extra Axes tutorial, in this section we will quickly demonstrate how axis position can be adjusted, how axis scale can be inverted and how minimum and maximum values can be controlled.

Positioning

With AnyChart you can place axes to any side if the chart, all you need to do is to adjust position attribute of <y_axis> or <x_axis> nodes.

Positioning depends on plot type and inversion of axes, you will find list of all possible positining and inversion settings in Axes Positioning and Inverting Templates.

And here is the demonstration of this feature on the Single-series sample:

Inversion

AnyChart allows to invert any axis: Y, X or any extra axis. Inversion is controlled by axis <scale>:

And here is the demonstration of Y Axis inversion on the Single-series sample:

Minimum and Maximum values control

By default AnyChart calculates axis minimum and maximum automatically, you can see this on the scale inversion chart sample above: minimal value on the Y Axis is 0.0, and maximum is 800.000. You can control these values by setting maximum and minimum attributes of <scale> node:

And here is the demonstration of maximum and minimum values on the Single-series sample:

Paddings between bars and bar groups

The special thing about bar charts are the paddings between bars and bar groups (in multi-series charts), on the picture below you can see what are these paddings:

If you want to set these paddings you need to set point_padding or group_padding attributes in <bar_series> node. Paddings are measured as a ratio to bar width (bars widths are calculated automatically). For example, if you set point_padding to 0.5 - the space between two bars will be equal to the half of each bar width. If you want to have no padding between bars or groups you should set point_padding or group_padding to 0.

Here is a sample of multi-series bar chart with point_padding and group_padding set to -0.1 and 2, accordingly, negative point_padding leads to bars overlay and large group_padding moves bar groups away from each other:

Using styles

In this section we will describe main parts of bar chart style and demonstrate how style can be created and applied. Also you will see list of predefined styles.

The main idea of styles is to segregate visualization and data definition. Visual appearance of bars is defined using certain styles and then you just apply the style to the certain data elements. Style can be applied to data series, data category or single bar.

Bar chart style is configured in <bar_style> and <bar_series> nodes. On the image below you can see what bar_style consists of: fill (including solid color fill, hatch fill, image fill and gradient fill), border and effects applied to whole bar.

Also, styles are used to make charts interactive, you can define how elements will be displayed by default, when selected, when user moves cursor over an element, etc.

Simple style

Now, let's look how to create a simple style and apply it to the chart. As we've already said style consists of several elements, here is an XML structure:

Using such settings we've created a style that defines bars of Gold color, rather thick border, hatch filled with DiagonalBrick and a couple of effects. Also, we've defined that when user will move cursor over an element it will be highlighted with a DarkRed thick border and hatch fill colored DarkRed too.

Now we will take a sample single-series chart described above, define style in XML and apply it to all chart elements, using <bar_series style="style1"/>

Application of different styles to chart elements

Now we will demonstrate how to apply different styles to different series and bars. To do it we will use multi-series sample that was demonstrated above and create two more styles: "style2" and "style3", both inherited from the "style1".

"style1" will be applied to "Year 2003 " series, "style2" will be applied to "Year 2004" series and "style3" will be applied to the bar with a highest value (Note - we will find highest value and set its style manually in this sample. But with AnyChart it is possible to do that automatically using Thresholds, read more about it in Thresholds tutorial).

So - the definitions of the styles are:

Style 1:

Style 2:
This style is inherited from "style1" and the only thing changed is a color of the fill: from "Gold" to "Rgb(180,180,255)". We've used styles inheritance to avoid duplication of the common settings.

Style 3:
This style is also inherited from "style1" and the new color of the fill is "Rgb(255,170,170)". And again we've used styles inheritance.

And, as a result here is an example of these styles usage:

Predefined styles

There are several predefined styles that you can use and modify with help of styles inheritance (setting them as a parent styles for your styles). On the picture below you can see how these styles will change an appearance of the bars and their names: "Default", "Silver", "AquaLight" and "AquaDark".

Note 1:
When you are inheriting from "AquaLight" and "AquaDark" styles you can change only the color, opacity, hatch-fill and effects of the bar.

Note 2:
When creating and applying styles to bars in 3D mode you can change only the color, opacity, hatch-fill and effects of the bar.

• You can read more about styles and their usage in Styles tutorial.
• Full reference of bar chart style can be found in XML Reference, particularly <bar_style> and <bar_series> nodes.
• General things about tuning visual appearance, working with borders, colors, fills, etc. - can be found in Visual Appearance Section

Working with data labels and tooltips

In this section we will explain how to add and configure data labels and tooltips. Full explanation of formatting and tuning visual appearance for them can be found in Labels and tooltips tutorials.

If you want to configure data labels and tooltips for all series - you should do that in <label_settings> and <tooltip_settings> sub-nodes of <bar_series> node. You can tune their visual appearance, positioning and format. Let's do that in the following example: we will make data labels appear to the right of the bars, also, we will format labels so they show only the value corresponding to the bar and tooltip will show detailed description.

When formatting data labels text and tooltip we will use formatting keywords:
{%CategoryName} - to show sales retail channel,
{%YValue} - to show sales,
{%SeriesName} - to show period (year),
{%YPercentOfSeries} - to show every retail channel sales percentage to total sales per year.

Related Help Topics:

• Learn more about labels and tooltips in Labels and tooltips
• Full Keywords reference and formatting guide: Labels and tooltips
• Full reference of data labels settings can be found in XML Reference, particularly <label_style> and <label_settings> nodes.

Using markers

Marker is an object with a specified shape, size, and color or an image used to mark and to identify chart elements. AnyChart allows to add markers to any data element including bars.

In the sample below we will take single-series data described above and mark the highest bar in series with a "Star5" of the "Gold" color.

To make marker visually appealing we will create a style, that will tell AnyChart to set marker size to 16 pixels in normal state, and make it bigger (22 pixels) when user moves cursor over an element.

Marker style "myMarker":

To apply marker to the certain we need to create <marker> sub-node in <point> and add
<marker enabled="True" style="myMarker"/>

And here is a result - the best retail channel for ACME Corp. is Discount Stores and we show this on the chart:

Working with colors and color palettes

AnyChart uses default color palette to colorize data elements of chart automatically even if you have not define special colors. But you can use your own palettes or palettes shipped with AnyChart. Also you can set and apply the color to exact data series or data point.

Setting colors to the elements

Let's demonstrate how to apply different colors to different data series. To apply the color to the exact series we need to set "color" attribute in the <series> node. In the sample below we have 5 series with sample data and we'll color each series to different color. Here is the sample:

In the sample below we will see how we can colorize individual points. We have chart with one series and predefined color for all elements. We will set "Rgb(180,77,77)" color for minimum point and "Rgb(77,180,77)" for the maximum one. As you see it is very easy to do by setting "color" attribute for <point> node.

Important Note:

AnyChart takes care of visualization and users convenience seriously - that is why we have a number of ways to set colors, for example, instead of "RGB(240,248,255)" you can set "HSB(208,100,97)" or "AliceBlue" or "#F0F8FF"- and the color will be the same. Depending on your system/site/application design you may need - and use - any of this color setting methods. But even this is not everything about colors in AnyChart: read more about setting colors below and in the following Help Sections:

• Different ways of setting colors of elements

Color palettes

AnyChart allows to apply color palettes to all series or to the exact series. In the first case each next series will take each next color from palette. If the number of the colors in palette is less than the number of series - palette will be looped. If you have only one series it will be colored by the first color in the palette. To apply palette to all series we have to set "palette" attribute in <data> node. Here it is:

When you have one series only, sometimes it is useful to color each point in series. You can do it by setting color of each point individually or you can apply a palette. For sure the second method is easier and more useful. To apply palette to the exact series you should set "palette" attribute for exact <series> node.

In the samples above we have shown usage of predefined palettes only, but AnyChart allows to create your own custom palettes. To learn more about it read Palettes tutorial.

Working with hatch fills and hatch palettes

AnyChart technology allows printing of charts. Some color printers print colors unpredictable and very often it is hard to identify similar colors. Also it is impossible to identify colors on prints of b/w (monochrome) printers. AnyChart has very useful feature - hatch fills, ideal for differentiating elements for black and white display or for those who are color blind. Hatch fill is fully-independent structure, it doesn't rely on color fill and it has own settings and palettes. To see whole range of available hatch types see Hatch tutorial.

Setting hatch fills to the elements

To demonstrate hatch fill feature we've prepared the following sample. As you see it is completely monochrome. We have chart with 5 series with 3 data points in each. For every series we've applied different hatch fills by setting "hatch_type" attribute for <series> node. Also we've changed hatch type for last element in 5th series by setting "hatch_type" attribute for <point> node.

Hatch palettes

When you have a lot of points or series it is very useful to use hatch palettes. Methods of working with hatch palette is very similar to color palette. You can apply hatch palette to all series or to exact series. In the first case each next series will take each next hatch type from palette. If the number of hatch types in palette is less than number of series - palette will be looped. If you have only one series each point will take the first hatch type from the palette. To apply palette to all series we have to set "hatch_palette" attribute in <data> node. Here it is:

When you have one series only you can can apply hatch palette to this series. To do it you should set "hatch_palette" attribute for <series> node. See the sample below:

In the samples above we have shown usage of predefined hatch palettes only, but AnyChart allows to create your own custom hatch palettes. To learn more about it read Hatch and hatch palettes .