[R] X11 font -adobe-helvetica size 15 could not be loaded

[Lisa Daniel]

HI All,

I got this Error message, when I tried to plot
 X11 font -adobe-helvetica-%s-%s-*-*-%d-*-*-*-*-*-*-*, face 5 at size 15 could not be loaded


sessionInfo()
R version 3.0.0 (2013-04-03)
Platform: x86_64-unknown-linux-gnu (64-bit)

locale:
 [1] LC_CTYPE=en_CA.UTF-8       LC_NUMERIC=C              
 [3] LC_TIME=en_CA.UTF-8        LC_COLLATE=en_CA.UTF-8    
 [5] LC_MONETARY=en_CA.UTF-8    LC_MESSAGES=en_CA.UTF-8   
 [7] LC_PAPER=C                 LC_NAME=C                 
 [9] LC_ADDRESS=C               LC_TELEPHONE=C            
[11] LC_MEASUREMENT=en_CA.UTF-8 LC_IDENTIFICATION=C       

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] stringr_0.6.2  reshape2_1.2.2

loaded via a namespace (and not attached):
[1] plyr_1.8    tools_3.0.0


I looked online for a solution.and found this (https://stat.ethz.ch/pipermail/r-help/2002-June/022116.html).  But, 

/etc/X11 $ ls
app-defaults             rgb.txt  xkb       Xresources  Xsession.options
default-display-manager  X        Xreset    Xsession    XvMCConfig
fonts                    xinit    Xreset.d  Xsession.d  Xwrapper.config

doesn't have XF86Config

 capabilities("X11")
 X11 
TRUE 
names(X11Fonts())
[1] "serif"        "sans"         "mono"         "Times"        "Helvetica"   
[6] "CyrTimes"     "CyrHelvetica" "Arial"        "Mincho" 


Then, I installed xfonts-100dpi, xfonts-75dpi (Ubuntu-based).
xset -q #output


Font Path:
  /usr/share/fonts/X11/misc,/usr/share/fonts/X11/Type1,built-ins
Regards,
Lisa.