On 12/04/2009 03:19 PM, Gabor Grothendieck wrote:
Thanks.
I am looking for the data to be just as if I had read in the png file (or
wmf file or whatever).
Hi,
You are after the binary payload of the rendered graph as a png file. So
you are going to have to go through a png file.
It would be nice to be able to render to a binary connection, like a
rawConnection, but it seems like an expensive "nice to have"
grid.cap seems to give a bitmap and then would
require some sort of processing to get the png or wmf, etc. form. Also note
that I need it for classic graphics and not just grid graphics.
grid.cap does not seem to care, baptiste code uses traditional graphics
What I have right now works just as I want it _except_ I have to create a
file and then read it back in which seems a waste.
Can you measure the time it takes to do dev.off() and readBin ?
On Fri, Dec 4, 2009 at 9:06 AM, baptiste auguie<
baptiste.aug...@googlemail.com> wrote:
Hi,
You can use grid.cap,
x11()
plot(1:10)
g = grid.cap()
dev.off()
str(g)
# chr [1:672, 1:671] "white" "white" "white" "white" "white" ...
but as far as I understand in ?grid.cap and the underlying code there
is no "capGrob" equivalent that wouldn't require opening a new device
before capturing the output.
I hope I'm mistaken.
Best,
baptiste
2009/12/4 Gabor Grothendieck<ggrothendi...@gmail.com>:
Currently I have an application that saves the current graphics image
(that
was created with classic graphics or grid graphics) to a file and then
reads
the file back in using readBin:
png("my.png")
plot(1:10)
dev.off()
raw.img<- readBin("my.png", "raw", size = 1, n = 100000000)
(I am doing this on Windows but would like to be able to do it on any
platform.)
Does the new raster functionality give me any way to get the object
raw.img
without creating the intermediate file, my.png? If so what is the
corresponding code?
On Mon, Nov 30, 2009 at 8:17 PM, Paul Murrell<p.murr...@auckland.ac.nz
wrote:
Hi
This is for developers of extension packages that provide extra
*graphics
devices* for R.
In the *development* version of R, support has been added to the
graphics
engine for sending raster images (bitmaps) to a graphics device. This
consists mainly of two new device functions: dev_Raster() and
dev_Cap().
The R_GE_version constant (in GraphicsEngine.h) has been bumped up to 6
as
a marker of this change.
This means that, at a minimum, all graphics devices should be updated to
provide dummy implementations of these new functions that just say the
feature is not yet implemented (see for example the PicTeX and XFig
devices
in the 'grDevices' package).
A full implementation of dev_Raster() should be able to draw a raster
image
(provided as an array of 32-bit R colors) at any size, possibly
(bilinear)
interpolated (otherwise nearest-neighbour), at any orientation, and with
a
per-pixel alpha channel. Where these are not natively supported by a
device, the graphics engine provides some routines for scaling and
rotating
raster images (see for example the X11 device). The dev_Cap() function
should return a representation of a raster image captured from the
current
device. This will only make sense for some devices (see for example the
Cairo device in the 'grDevices' package).
A little more information and a couple of small examples are provided at
http://developer.r-project.org/Raster/raster-RFC.html
Paul
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Department of Statistics
The University of Auckland
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Auckland
New Zealand
64 9 3737599 x85392
p...@stat.auckland.ac.nz
http://www.stat.auckland.ac.nz/~paul/<http://www.stat.auckland.ac.nz/%7Epaul/>
<http://www.stat.auckland.ac.nz/%7Epaul/>
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