gridSVG (version 1.4-3)

viewportCreate: Recreate a viewport from imported coordinate information.

Description

Creates a viewport object that is positioned in the same location as a previously exported viewport.

The purpose of this function is so that we can recreate content for later manipulation.

Usage

viewportCreate(vpname, newname = NULL,
               vpPath.sep = getSVGoption("vpPath.sep"))

Arguments

vpname

The name of the viewport to be recreated, as stored in coordinate information. This is most likely a viewport path.

newname

The name that is going to be assigned to the viewport as it is re-created. If this parameter is NULL, then the name is taken to be the last viewport in listed in vpname (because it is usually a viewport path).

vpPath.sep

The viewport path separator that was used for vpname.

Value

• A viewport object.

Details

In order to use this function, coordinate information must be available to gridSVG. This means that viewport information must be imported using gridSVGCoords.

The ROOT viewport must also have coordinate information imported because the created viewport is positioned relative to this.

Examples

require(grid)

  grid.newpage()

  # Pushing a new VP to draw a rect within
  pushViewport(viewport(x = unit(0.3, "npc"), y = unit(0.2, "npc"),
                        width = unit(0.1, "npc"), height = unit(0.3, "npc"),
                        xscale = c(0, 20), yscale = c(0, 10),
                        name = "testVP"))
  grid.rect()
  grid.export("create-test.svg", exportCoords = "file")

  # Importing coordinate information
  gridSVGCoords(readCoordsJS("create-test.svg.coords.js"))

  # This should appear to be the same rect
  grid.newpage()
  pushViewport(viewportCreate("testVP.1"))
  grid.rect()

  # Let's see if the scales are accurate, should be:
  # xscale: [0, 20]
  # yscale: [0, 10]
  current.viewport()$xscale
  current.viewport()$yscale