Documentation
Table of Contents
16 Pie chart
Overview
The pie chart widget allows to display values of selected items as a pie or doughnut chart.
 Pie chart. |
 Doughnut chart. |
On mouseover, the focused sector pops out and the legend for this sector is displayed. Clicking on the focused sector makes the pop-out effect permanent, until closed with "x".
The charts are drawn using a vector image drawing technique.
Configuration
To configure, select Pie chart as type:
Data set
The Data set tab allows to select data for the pie chart by adding data sets.
Two types of data sets can be added:
- Item pattern - data from matching items is displayed. Automatically picked distinctive colors are used to draw the chart.
- Item list - data from selected items is displayed. Colors may be adjusted for each displayable item.
By default an Item pattern data set is added. When adding a new data set, it is possible to select between Item pattern/Item list data sets, by clicking on the downward pointing icon next to the Add new data set button and selecting the required option. Note that only numeric item types are allowed.
| Data set | For Item pattern data set: Enter the host and item patterns: data of items that match the entered patterns will be displayed on the pie chart. Wildcard patterns may be used for selection (for example, * will return results that match zero or more characters).To specify a wildcard pattern, just enter the string manually and press Enter. An important feature is that if you start typing characters, a dropdown list will show matching hosts/items. See also: Data set configuration details. Host pattern and item pattern parameters are mandatory. The wildcard symbol is always interpreted, therefore, it is not possible to add, for example, an item named item* individually, if there are other matching items (e.g., item2, item3). For Item list data set: Select items for the pie chart by clicking on the Add button. A color picker is displayed in front of the selected item name. The Type dropdown after the item name allows to select display type for each item: Normal - item value is represented proportionally on the pie chart (default); Total - item value takes up the whole pie chart. Only one Total item can exist per pie chart, and it will be placed first on the pie chart legend. Also, Data set aggregation (see below) will be disabled and set to "None" if a Total item is added. When configuring the widget on a template dashboard, the parameter for specifying host patterns is not available, and the parameter for specifying an item list allows to select only the items configured on the template. |
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| Aggregation function | Specify which aggregation function to use for each item in the data set: min - display the smallest value; max - display the largest value; avg - display the average value; sum - display the sum of values; count - display the count of values; first - display the first value; last - display the last value (default). Aggregation allows to display an aggregated value for the interval (5 minutes, an hour, a day) selected in the Time period tab or used for the whole dashboard. |
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| Data set aggregation | Specify which aggregation function to use for the whole data set: none - no aggregation, items are displayed separately (default); min - display the smallest value; max - display the largest value; avg - display the average value; sum - display the sum of values; count - display the count of values. Aggregation allows to display an aggregated value for the interval (5 minutes, an hour, a day) selected in the Time period tab or used for the whole dashboard. |
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| Data set label | Specify a custom label for the data set. The label is displayed in the data set configuration and the pie chart legend (for aggregated data sets). All data sets are numbered including those with a specified Data set label. If no label is specified, the data set will be labeled automatically according to its number (e.g. "Data set #2", "Data set #3", etc.). Data set numbering ir recalculated after reordering/dragging data sets. Data set labels that are too long will be shortened to fit where displayed (e.g. "Number of proc..."). |
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Displaying options
The Displaying options tab allows to define history data selection and visualization options for the pie chart:
| History data selection | Select the data source: Auto - data are sourced according to the classic algorithm (default); History - data from history; Trends - data from trends. |
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| Draw | Select the visualization style of the pie chart: Pie - a full pie (sectors take up 100% of the radius); Doughnut - a pie with empty circle in the middle (sectors use up to 50% of radius). |
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| Space between sectors | Select the space size (in units of 0-10) between sectors (default is "1"). | ||
| Merge sectors smaller than N% | Mark the checkbox to merge sectors smaller than the N%. If enabled, select the color for the merged sectors and the percentage threshold (N) for merging small sectors. |
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| Draw style: Doughnut | |||
| Width | Select the doughnut width: 20, 30, 40 or 50% (default) of the radius. | ||
| Show total value | Mark the checkbox to show the total value in the middle of the doughnut chart. | ||
| Size | Select the size option for the total value: Auto - the text is sized automatically to fit the doughnut middle readably; Custom - specify the text size as height percentage from the total widget height. |
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| Decimal places | Specify the number of decimal places for the total value (0-6). | ||
| Units | Specify the units for the total value. | ||
| Bold | Mark the checkbox to display the total value in bold. | ||
| Color | Select the color for the total value. | ||
Time period
The Time period tab allows to set a custom time period:
| Set custom time period | Mark this checkbox to set a custom time period for the aggregation settings of the pie chart. If set, a clock icon will be displayed in the top right corner of the widget, indicating the set time on mouseover. If unmarked (by default), the whole dashboard time settings will be used. |
| From | Set the start time of the custom time period. |
| To | Set the end time of the custom time period. |
Legend
The Legend tab allows to customize the pie chart legend:
| Show legend | Unmark this checkbox to hide the legend on the pie chart (marked by default). |
| Show aggregation function | Mark this checkbox to show the aggregation function in the legend. |
| Number of rows | Set the number of legend rows to be displayed (1-10). |
| Number of columns | Set the number of legend columns to be displayed (1-4). |
The information displayed by the pie chart widget can be downloaded as a .png image using the widget menu.
A screenshot of the widget will be saved to the Downloads folder.
Data set configuration details
The Host pattern and Item pattern fields in the Data set tab both recognize full names or patterns containing a wildcard symbol (*).
This functionality allows selecting all the hosts and items whose names contain the selected pattern.
For more details, see Graph widget.