NOTE: Sections 8.1 through 8.6 refer to dataset organization and techniques previous to the Discrete Sampling Geometries Standard in CF. Skip to Section 8.10 for discussion of Discrete Sampling Geometries data. Support for Discrete Sampling Geometries datasets begins with PyFerret/Ferret v7.6. Collections of this kind of data are named "Trajectory" data by the Discrete Samplin Geometries standard.
Lagrangian data (ship tracks, drifters, etc.) is a special case of scattered point data described in a preceding section. In the terminology of "Defining gridded variables from point data" Lagrangian data is simply point data organized onto a 1-dimensional time axis grid.
8.6.1 Visualization techniques for Lagrangian data
Ferret has several visualization tools that specifically address the needs of Lagrangian data. There are three scripts:
|
polymark (polymark_demo) |
marks value-colored symbol at each location |
|
polytube (polytube_demo) |
creates a line following the Lagrangian track with color varying according to a Lagrangian variable |
|
trackplot (trackplot_demo) |
creates a line plot of a Lagrangian variable where the zero line of the plot follows the Lagrangian track |
Overlays of the trackplot script are useful to visualize more than one variable. Run the demonstration scripts noted above for each tool for an example of its use with Lagrangian data.