# Median does not work directly on c(XXa$red,XXb$red,XXc$red)!!

require(pixmap)
XXa<-attributes(read.pnm("Calcite01a.ppm"))
XXb<-attributes(read.pnm("Calcite01b.ppm"))
XXc<-attributes(read.pnm("Calcite01c.ppm"))
XXd<-attributes(read.pnm("Calcite01d.ppm"))
XXe<-attributes(read.pnm("Calcite01e.ppm"))

rows<- XXa$size[1]
cols<- XXa$size[2]

XXblu<-XXgre<-XXred<- matrix(0, rows,cols)

XXred<- (XXa$red+XXb$red+XXc$red+XXd$red+XXe$red)/5
XXblu<- (XXa$blue+XXb$blue+XXc$blue+XXd$blue+XXe$blue)/5
XXgre<- (XXa$green+XXb$green+XXc$green+XXd$green+XXe$green)/5
dat<- array(c(XXred, XXgre, XXblu), c(attributes(XXred)$dim,3))
XX<- pixmapRGB(dat)
write.pnm(XX, file="Calcite01avg.ppm")
cat("Avg Done\n") 

rm(list=ls())
cat("All Done\n")