png                   package:base                   R Documentation

_J_P_E_G _a_n_d _P_N_G _g_r_a_p_h_i_c_s _d_e_v_i_c_e_s

_D_e_s_c_r_i_p_t_i_o_n:

     A graphics device for JPEG or PNG format bitmap files.

_U_s_a_g_e:

     jpeg(filename = "Rplot.jpeg", width = 480, height = 480, pointsize = 12,
          quality = 75, ...)
     png(filename ="Rplot.png", width = 480, height = 480, pointsize = 12, ...)

_A_r_g_u_m_e_n_t_s:

filename: the name of the output file.

   width: the width of the device in pixels.

  height: the height of the device in pixels.

pointsize: the default pointsize of plotted text.

 quality: the `quality' of the JPEG image, as a percentage. Smaller
          values will give more compression but also more degradation
          of the image.

    dots: additional arguments to the `X11' device.

_D_e_t_a_i_l_s:

     Plots in PNG and JPEG format can easily be converted to many other
     bitmap formats, and both can be displayed in most modern web
     browsers. The PNG format is lossless and is best for line diagrams
     and blocks of solid colour. The JPEG format is lossy, but may be
     useful for image plots, for example.

     R can be compiled without support for either or both of these
     devices: this will be reported if you attempt to use them on a
     system where they are not supported.  They will not be not
     available if R has been started with `--gui=none' (and will give a
     different error message).

_V_a_l_u_e:

     A plot device is opened: nothing is returned to the R interpreter.

_N_o_t_e:

     These are based on the `X11' device, so the additional arguments
     to that device work, but are rarely appropriate.  The colour
     handling will be that of the `X11' device in use.

_A_u_t_h_o_r(_s):

     Guido Masarotto and Brian Ripley

_S_e_e _A_l_s_o:

     `Devices', `dev.print', `bitmap'.

     `capabilities' to see if these devices are supported by this build
     of R.

_E_x_a_m_p_l_e_s:

     ## copy current plot to a PNG file
     dev.print(png, file="myplot.png", width=480, height=480)

