VCS: Visualization Control System¶
What is VCS?¶
The PCMDI Visualization Control System (VCS) is expressly designed to meet the needs of scientific community. VCS allows wide-ranging changes to be made to the data display, provides for hardcopy output, and includes a means for recovery of a previous display.
In the VCS model, the data display is defined by a trio of named object sets, designated the “primary objects” (or “primary elements”). These include:
Data Ingestion: The data, which drives the visualization is ingested into the system via cdms2 or other numeric modules such as numpy;.
Graphics Method: The graphics method, which specifies the display technique.
Template: The picture template, which determines the appearance of each segment of the display. Tables for manipulating these primary objects are stored in VCS for later recall and possible use.
In addition, detailed specification of the primary objects’ attributes is provided by eight “secondary objects” (or secondary elements”):
colormap: Specification of combinations of 256 available colors
fill area: Style, style index, and color index
format: Specifications for converting numbers to display strings
line: Line type, width and color index
list: A sequence of pairs of numerical and character values
marker: Marker type, size, and color index
text: Text font type, character spacing, expansion and color index
text orientation: Character height, angle, path, and horizontal/vertical alignment
By combining primary and secondary objects in various ways (either at the command line or in a program), the VCS user can comprehensively diagnose and intercompare climate model simulations. VCS provides capabilities to:
View, select and modify attributes of data variables and of their dimensions
Create and modify existing template attributes and graphics methods
Save the state-of-the-system as a script to be run interactively or in a program
Save a display as a Computer Graphics Metafile (CGM), GIF, Postscript, Sun Raster, or Encapsulated Postscript file
Perform grid transformations and compute new data variables
Create and modify color maps
Zoom into a specified portion of a display
Change the orientation (portrait vs. landscape) or size (partial vs. full-screen) of a display
Animate a single data variable or more than one data variable simultaneously
Display data in various geospatial projections
For an overview of the concepts present in VCS, we recommend checking out the User Guide.
VCS is published under the Apache 2.0 License. Its source code can be found at https://github.com/uv-cdat/vcs