qplot and anti-aliasing in R

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被撕碎了的回忆 2021-02-07 03:47

I am using ggplot2 library and am working with the qplot command I know I can save my output as an anti-aliased image file by using the following command after my qplot

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  •  北荒
    北荒 (楼主)
    2021-02-07 04:29

    Ok, I just checked. I was wrong in my earlier comment. From help(x11) where a lot of detail is available -- the new Cairo-based devices do have anti-aliasing available:

    x11 package:grDevices R Documentation

    X Window System Graphics

    Description:

     ‘X11’ starts a graphics device driver for the X Window System
     (version 11).  This can only be done on machines/accounts that
     have access to an X server.
    
     ‘x11’ is recognized as a synonym for ‘X11’.
    

    Usage:

     X11(display = "", width, height, pointsize, gamma, bg, canvas,
         fonts, xpos, ypos, title, type, antialias)
    
     X11.options(..., reset = FALSE)
    

    Arguments:

    [...]

     fonts: X11 font description strings into which weight, slant and
          size will be substituted.  There are two, the first for fonts
          1 to 4 and the second for font 5, the symbol font.  See
          section ‘Fonts’. 
    

    [...]

     antialias: for cairo types, the typeof anti-aliasing (if any) to be
          used.  One of ‘c("default", "none", "gray", "subpixel")’. 
    

    [...]

    Details:

     The defaults for all of the arguments of ‘X11’ are set by
     ‘X11.options’: the ‘Arguments’ section gives the ‘factory-fresh’
     defaults.
    
     The initial size and position are only hints, and may not be acted
     on by the window manager.  Also, some systems (especially laptops)
     are set up to appear to have a screen of a different size to the
     physical screen.
    
     Option ‘type’ selects between two separate devices: R can be built
     with support for neither, ‘type = "Xlib"’ or both.  Where both are
     available, types ‘"cairo"’ and ‘"nbcairo"’ offer
    
        * antialiasing of text and lines.
    
        * translucent colours.
    
        * scalable text, including to sizes like 4.5 pt.
    
        * full support for UTF-8, so on systems with suitable fonts you
          can plot in many languages on a single figure (and this will
          work even in non-UTF-8 locales).  The output should be
          locale-independent.
    
     ‘type = "nbcairo"’ is the same device as ‘type="cairo"’ without
     buffering: which is faster will depend on the X11 connection.
     Both will be slower than ‘type = "Xlib"’, especially on a slow X11
     connection as all the rendering is done on the machine running R
     rather than in the X server.
    
     All devices which use an X11 server (including the ‘type = "Xlib"’
     versions of bitmap devices such as ‘png’) share internal
     structures, which means that they must use the same ‘display’ and
     visual.  If you want to change display, first close all such
     devices. 
    

    [...and more...]

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