# Explore a pgtraj

#### Balázs Dukai

#### 2018-03-02

Note that in order to explore a pgtraj, all pgtrajes in the same traj schema need to have and SRID assinged to them. Currently (v0.6.0) there is no function in `rpostgisLT` to assign an SRID to a pgtraj, thus you need to assign a projection to the `ltraj` and import that with `ltraj2pgtraj()`. When `explorePgtraj()` is launched, it checks whether the required materialized views exist in the provided schema and tries to create them if they don’t, using the `createShinyViews()` function. The mention materialized views are `all_burst_summary_shiny` and `step_geometry_shiny_<pgtraj>`.

`explorePgtraj` can display three subsets of a trajectory, the full trajectory, bursts and steps. The full trajectory is always displayed in pale yellow and it is assigned to the Full trajectory layer in the layer control. The bursts of a trajectory are assigned to the Bursts layer and displayed with dashed line. You can select the bursts you want to display in the Bursts selection box. The display of steps are currently (v0.6.0) assigned to the layers Steps-1 and Steps-2. You need to turn both off if you want to hide the steps. You can select which steps to display by adjusting the Time window. To step through a trajectory, use the Prev and Next buttons, or the left/right arrow keys.

If you use the keys or buttons to explore a trajectory, you can set the amount of time increment in the Increment input box. Additionally, you can adjust the “width” of the Time window in the Interval input box.

The color of both the bursts and steps are governed by the Color switch. The colors are assigned either by the burst name or by the animal name. Note that the color scheme

User interface of explorePgtraj