[BioC] Variations of plotting symbols

[Ochsner, Scott A]

Dear BioC,

I have five microarray datasets each with two levels.  I'm plotting a PCA figure and would like to avoid using color as page charges for color in the journal I wish to submit are expensive.

Is there a way to turn the solid triangle symbol (pch=17) 180 degrees?  This would add enable me to use the upside down triangle (open and solid) as another symbol set. 

> sessionInfo()
R version 2.7.0 (2008-04-22) 
i386-pc-mingw32 

locale:
LC_COLLATE=English_United States.1252;LC_CTYPE=English_United States.1252;LC_MONETARY=English_United States.1252;LC_NUMERIC=C;LC_TIME=English_United States.1252

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

other attached packages:
 [1] affycoretools_1.12.0 annaffy_1.12.1       KEGG.db_2.2.0        gcrma_2.12.1         matchprobes_1.12.0   biomaRt_1.14.0      
 [7] RCurl_0.9-3          GOstats_2.6.0        Category_2.6.0       RBGL_1.16.0          GO.db_2.2.0          graph_1.18.1        
[13] limma_2.14.2         affy_1.18.1          preprocessCore_1.2.0 affyio_1.8.0         MLInterfaces_1.14.1  annotate_1.18.0     
[19] xtable_1.5-2         AnnotationDbi_1.2.1  RSQLite_0.6-8        DBI_0.2-4            rda_1.0              rpart_3.1-41        
[25] genefilter_1.20.0    survival_2.34-1      MASS_7.2-41          Biobase_2.0.1       

loaded via a namespace (and not attached):
[1] class_7.2-41    cluster_1.11.10 XML_1.95-2  

Scott A. Ochsner, Ph.D.
NURSA Bioinformatics
Molecular and Cellular Biology
Baylor College of Medicine
Houston, TX. 77030
phone: 713-798-6227