Local TOC
General (toc)
Purpose: analysis of sailing, weather and sea conditions regarding current and historic tracks. A precondition for its benefit is, that you register these conditions when cruising.
The Piechart subpage - or just 'Piechart' - opens from:
- Track mainpage when tracking ( Piechart button)
- History mainpage ( Piechart button)
- Tracklist action dialog (Open Piechart action)
Its content is based on:
- what is being / has been tracked
- time range:
- for a given track
- set by The Datepickers
- Behaviour setting of Windforces
The Piechart subpage - as well as the Barchart subpage - is based on the Charts library licensed under Apache License 2.0 - Copyright 2015 Daniel Cohen Gindi & Philipp Jahoda.
The duet picker panel (toc)
is placed at the top and consists of two independant wheels:
The Attribute picker to the left selects what to show:
- Sails
- Engine
- Wind direction
- Wind force
- Current direction
- Current force
- Weather
- Waves
- Temperature
- Visibility
The Timeunit picker to the right selects how to show:
- Percent
- Days
- Hours
- Minutes
Calculation rules (toc)
Each type of attribute can have several discrete values, as shown in e.g. the Pickerscreen example. The distribution of these values are shown in the corresponding chart. Calculations follow these rules:
- each track within The Datepickers scope given, is treated individually (time between tracks don't count)
- the time from departure until a first specified value is found counts as unset / no registration (labelled -?-). Exceptions are:
- for the Sails attribute: if unspecified at departure, it counts as No sails *)
- for the Engine attribute: if unspecified at departure, it counts as No engine *)
*) Check description of assumption switches in The switches section.
Time range display (toc)
The example below shows how the selected time range is displayed at the bottom of the Piechart, together with the number of tracks involved - and a legend:
Examples (toc)
Below a series of screenshots of charts follow. Registrations from the first 6 tracks of the Appetizer 2: roundtrip through Sweden were used:
Example 1: sails shown in percent (toc)
48 perent of the time, full sails were worn. Pie slices always represent non-zero values - so to reveal what the zero display for Sails, 2.reef means, the Timeunit picker wheel is dragged from Percent to Minutes:
Example 2: sails shown in minutes (toc)
It appears, that Sails, 2.reef was the situation during 8 minutes (was rounded to zero percent above).
Example 3: wind directions (toc)
where the -?- stands for unset / no registration (3 percent of the time).
Example 4: wind forces (toc)
Example 5: changing color (toc)
Pie slice colors are random and change each time the chart is displayed. If a chart is hard to read because of unfortunate choise of colors, use the button to select another set:
Example 6: turning and highlighting (toc)
Selecting a slice by tapping it, highlights it and informs on the number of registrations from which the slice is build - here 4 registration(s):
A chart can be turned by tapping, holding and dragging a slice. This can improve readability of the text on a slice when it's is eclipsed by that of another slice.
A tap at the bottom of the chart un-selects the slice and revokes the Time range display.
Example 7: empty chart when no data (toc)
If nothing was registered for an attribute type for tracks in the given time range, the chart turns monochrome:
In this case, no current direction was registered for a single track (day), so the label is -?-. This is not the same as actively registering no current, which is represented as nil.
Active registration of nil is possible for:
- Wind direction
- Wind force
- Current direction
- Current force
Example 6: Piechart opened from Track mainpage (toc)
In the previous examples, the chart is opened by tapping the Piechart button on the History mainpage - indicated by the back button in the green navigation bar.
However, the chart may just as well be opened by tapping the Piechart button on the Track mainpage - the back button then displays as :
Functionality is the same, whether opened from the History or the Track mainpage. In the latter case, the time range is setup as:
- From: Departure time, i.e. the time you started tracking
- Till: Arrival time so far, i.e. the time the last plot was done when the chart was opened
Like the Barchart subpage, the chart is static, i.e. it doesn't change after being opened, even if tracking is active.
Sailor Logbook S App manual - © Copyright 2018 CoaSoft ApS Denmark