[R] High resolution plots

[Knut Krueger]

Knut Krueger schrieb:

>Is there any possibility to get high resolution plots in a windows xp 
>system?
>I tried it with the device function png(filename = 
>"c:/r/highresplot%d.png",pointsize=12, res=900)
>but when I try to set: width = 480, height = 480 or   pointsize = 12, 
>the text is not scaled in the same way as the plots.
>

There are three bmp based functions available;:
bmp, jpeg, png

bmp is without compression so I decided not to use it 
jpeg is no loss less compression so I decided not to use it 
the third was png

Now I tried the other one and I think that there is a bug in the png code or I do not understand the reason:

jpeg(filename = "c:/r/Rplot%03d.jpg", width = 960, height = 960, pointsize = 24, quality = 100, bg = "white", res = 2400)
witdh/heigth  = 960  <> 10.16 mm
ppi=2400
Results as expected


jpeg(filename = "c:/r/Rplot%03d.jpg", width = 1920, height = 1920,
          pointsize = 48, quality = 100, bg = "white", res = 2400)

witdh/heigth  = 1920  <> 20.32 mm
ppi=2400
Results as expected


bmp(filename = "c:/r/Rplot%03d.bmp", width = 1920, height = 1920, pointsize = 48, bg = "white", res = 2400)
witdh/heigth  = 1920  <> 20.32 mm
ppi=2400
Results as expected


png(filename = "c:/r/Rplot%03d.png", width = 1920, height = 1920, pointsize = 48, bg = "white", res = 2400)

witdh/heigth  = 1920  <> 20.32 mm
ppi=150
Result not as expected.

Ok I am able to use the jpeg or bmp format, but does anybody know why the png function does not work in the same way as the jpeg and bmp function?

Regards Knut