The Charts screen can show a separate chart for each session of collected position data. Each session can cover an extended period, such as a full night's sleep. (Sessions are separated by gaps of four or more hours without collected data.) Tapping a chart will show or hide additional information and a chart toolbar. You can change from one chart to another by swiping left or right, or by using the arrow buttons on the chart toolbar.

Chart example

Each chart shows the full duration of its session, starting near the top of the screen and extending to the tab bar at the bottom, with time labels along the left side. (The format of the time labels, such as the use of 12-hour or 24-hour formats, depends of your device settings.)

Sleep position information is indicated by a bright line on the chart. The left-to-right position of the line corresponds to the changing left or right tilt of the device. The middle portion of the chart indicates a face-up position, the left side indicates a left-facing position, and the right side indicates a right-facing position. (Areas near the left and right edges of the chart both indicate positions that are close to a face-down position. You can think of the chart as wrapping around from one edge to the other, much like a map of the world.)

Dark vertical grid lines are spaced 45 degrees apart. The spacing of the horizontal grid lines depends on the duration of the session shown. The “red zone” in the middle of the chart shows the range of positions that can trigger the face-up alarm (if it is on) and the counting of face-up episodes (shown on the main screen).

The color of the chart line indicates whether the device was upright. It is white for times when the device (and, presumably, its wearer) was lying down, and blue for more upright positions (as when the wearer was sitting or standing). When the wearer is walking around, the blue line tends to shift significantly from side to side, often causing a blue band across much of the chart.

Overlay at top of chart

Tapping on a chart will show or hide a translucent overlay of additional information, and a chart toolbar near the bottom of the screen. By default the overlay appears near the top of the screen, but it can be dragged up and down to other positions.

On the chart toolbar, the “action” button (leftmost) displays a menu that allows you to save a chart as a photo, email a chart image, or email chart data. The arrow buttons change the displayed chart, and the “trash” button allows you to delete an entire session.

Toolbar at bottom of chart

The red badge on the Charts tab shows the approximate total duration of all the position data currently stored on your device by SomnoPose. Although SomnoPose imposes no specific limit on the amount of data it can handle, keeping data from many nights may cause slower performance for startup, deletions and other operations.