grid.raster {grid} | R Documentation |
Render a raster object (bitmap image) at the given location, size, and orientation.
grid.raster(image, x = unit(0.5, "npc"), y = unit(0.5, "npc"), width = unit(1, "npc"), height = NULL, just = "centre", hjust = NULL, vjust = NULL, interpolate = TRUE, default.units = "npc", name = NULL, gp = gpar(), vp = NULL) rasterGrob(image, x = unit(0.5, "npc"), y = unit(0.5, "npc"), width = unit(1, "npc"), height = NULL, just = "centre", hjust = NULL, vjust = NULL, interpolate = TRUE, default.units = "npc", name = NULL, gp = gpar(), vp = NULL)
image |
Any R object that can be coerced to a raster object. |
x |
A numeric vector or unit object specifying x-location. |
y |
A numeric vector or unit object specifying y-location. |
width |
A numeric vector or unit object specifying width. |
height |
A numeric vector or unit object specifying height. |
just |
The justification of the rectangle
relative to its (x, y) location. If there are two values, the first
value specifies horizontal justification and the second value specifies
vertical justification. Possible string values are: "left" ,
"right" , "centre" , "center" , "bottom" ,
and "top" . For numeric values, 0 means left alignment
and 1 means right alignment.
|
hjust |
A numeric vector specifying horizontal justification.
If specified, overrides the just setting. |
vjust |
A numeric vector specifying vertical justification.
If specified, overrides the just setting. |
default.units |
A string indicating the default units to use
if x , y , width , or height
are only given as numeric vectors. |
name |
A character identifier. |
gp |
An object of class gpar , typically the output
from a call to the function gpar . This is basically
a list of graphical parameter settings. |
vp |
A Grid viewport object (or NULL). |
interpolate |
A logical value indicating whether to linearly interpolate the image (the alternative is to use nearest-neighbour interpolation, which gives a more blocky result). |
Only one of width
or height
needs to be specified,
in which case, the aspect ratio of the image is preserved. If
both width
and height
are specified, it is likely
that the image will be distorted.
Not all graphics devices are capable of rendering raster images and some may not be able to produce rotated images (i.e., if a raster object is rendered within a rotated viewport).
All graphical parameter settings in gp
will be ignored,
including alpha
.
A rastergrob grob.
Paul Murrell
redGradient <- matrix(hcl(0, 80, seq(50, 80, 10)), nrow=4, ncol=5) # interpolated grid.newpage() grid.raster(redGradient) # blocky grid.newpage() grid.raster(redGradient, interpolate=FALSE) # blocky and stretched grid.newpage() grid.raster(redGradient, interpolate=FALSE, height=unit(1, "npc")) # The same raster drawn several times grid.newpage() grid.raster(0, x=1:3/4, y=1:3/4, w=.1, interp=FALSE)