Pie Chart+

Overview

When to use it

Use Pie Chart+ when you need to:

• Show how much each of a few values contributes to a total, such as energy use by area.
• Show the total in the center of a donut next to its parts.
• Compare shares at the current display time, or as averages over the display time range.

Choose Combo Chart+ when you must compare precise values, show many categories, or follow values over time.

Before you begin

• Prepare two or more numeric PI Points or AF attributes. Each data source becomes one slice.
• Use values that are parts of the same total, in compatible units. Pie Chart+ adds the values as they are and does not convert units.
• Keep the number of slices small, so that labels and colors stay distinguishable.

Add and set up the symbol

1. Select Pie Chart+ in the PI Vision symbol gallery.
2. Drag the numeric data sources onto the symbol.
3. Right-click the symbol and select Configure Pie Chart.
4. Under Type, select Donut.
5. Under Total, set Enabled to ON.
6. Close the pane. The symbol shows one slice per data source, each labeled with its share, and the sum of all slices in the center.

Common tasks

Choose the chart layout

Use this when the default pie does not fit, for example when you want a total in the middle or a layout that needs less height.

1. Right-click the symbol and select Configure Pie Chart.
2. Under Type, select a layout button (1): Pie, Donut, Donut Half, or Polar.
3. For a donut or half donut, drag the Radius slider (2) to change the size of the opening.

Layout	Example	What it shows
Pie		A full circle. Compare the angle of each slice.
Donut		A ring with an open center that can hold a total.
Donut Half		A semicircle. Use it when the symbol is wide and low.
Polar		Equal-angle wedges whose length shows the value. Compare lengths instead of angles.

Show each slice's share as a percentage

Use this when readers care about proportion more than the raw values.

1. In the configuration pane, open Data Labels.
2. Make sure Show is ON.
3. Set Name (1) and Value (2) to OFF.
4. Set Percent (3) to ON.
5. Optionally set Position to Inside, Outside, or Auto.

Each slice shows its share of the total. To show the same figure in the legend, see Place and format the legend.

Put a total in the center of a donut

Use this when readers need the sum of all slices next to the parts. Select the Donut or Donut Half layout first.

1. In the configuration pane, open Total.
2. Set Enabled (1) to ON.
3. Set Label (2) to ON to print the word "Total" above the number.
4. In Units (3), select the unit to print after the number.
5. In Decimals (4), select how many decimals to show.

The center of the donut shows the sum of all slice values. Units only adds text after the number. It lists the units of your data sources and does not convert anything.

Place and format the legend

Use this when the legend crowds the chart or must show more than names.

1. In the configuration pane, open Legend.
2. In Position (1), select Top, Right, Bottom, or Left.
3. In Alignment (2), select where the legend sits along that edge.
4. In Format (3), select what each entry shows, for example Name, Percent.

The legend moves to the chosen edge and each entry shows the chosen fields. A legend at the top or bottom wraps into more rows; when those rows would take more than about a third of the symbol height, or the legend is at the left or right, it adds page arrows with a page count such as 1/2 instead.

Change a slice color

Use this when a slice must match a color that your operators already know.

1. In the configuration pane, open Trace Options.
2. Select the data source in the list (1).
3. Under Options, open the Color list (2) and select a color.

The slice for that data source changes color, and its legend marker follows. To paint every slice in one color, set Mode under Coloring to Single.

Show averages instead of the current value

Use this when the shares should reflect a period, such as the last eight hours, and not a single moment.

1. In the configuration pane, open Trace Options.
2. Select a data source in the list (1).
3. Set Value Type (2) to Average. Other choices are Maximum, Minimum, StdDev, pStdDev, and Range.
4. Repeat steps 2 and 3 for each data source.

The symbol uses the range in the PI Vision time bar. Slice sizes show each data source's average over that range.

Use the symbol

• Hover a slice to see its tooltip. The tooltip shows the value with its unit and the slice's percentage of the total.
• Legend pages: when the legend shows page arrows, use them to move between pages.
• Display time: the slices follow the PI Vision display time. In a live display they update with new values. When you change the display time range, the symbol shows the values for that range.
• The symbol only displays data. It does not write to the PI System or change other symbols.

Configure the symbol

Right-click the symbol and select Configure Pie Chart. Groups appear in this order. Groups that apply only to some layouts say so.

Type

Title

Style

Coloring

Legend

Axis Y and Grid

Both groups appear only when the layout is Polar.

Data Labels

Total

Not available when the layout is Polar. Use it with Donut or Donut Half: on a plain pie the total is drawn over the slices.

Tooltip

Trace Options

Troubleshooting and limitations

Limitation: The total adds the slice values as they are. It does not convert units.